Project 1974 MGB GT - The Mustard (Mit) Mobility Scooter - 6yrs ownership & the end is potentially nigh!

[Sigmund Fraud]

ARGHHHHHHHHHHHHHHHHHHHHHHH x 1000

 

Bit of bad luck there, but it should all be fairly simple and cheap to fix.

 

As you have found out, modern reproduction rubber stuff is usually shite. Unfortunately, NOS rubber is rarely better, as it's usually dried out after 40 years in storage and will crumble away in no time.

 

I usually go ahead with repro rubber, coat it liberally in red rubber grease (avoid copper grease or lithium grease !) and hope for the best. Polyurethane can be brilliant, but quality and fit vary enormously and there are plenty of horror stories around describing suspension arm failure due to dry poly bushes that have seized.

 

Regarding the bolts, I'd recommend investing in a new, high-tensile set and replacing the castle nuts with nylocs - you're likely to lose several "concours" points, but nylocs are much easier to work with !

[danthecapriman]

Modern rubber is absolute wank. I put new rubber dust covers on the Volvo's front calliper sliders early this year and checking them recently they've all perished already! Less than 1 year is terrible quality!

[SiC]

Bit of bad luck there, but it should all be fairly simple and cheap to fix.

 

As you have found out, modern reproduction rubber stuff is usually shite. Unfortunately, NOS rubber is rarely better, as it's usually dried out after 40 years in storage and will crumble away in no time.

 

I usually go ahead with repro rubber, coat it liberally in red rubber grease (avoid copper grease or lithium grease !) and hope for the best. Polyurethane can be brilliant, but quality and fit vary enormously and there are plenty of horror stories around describing suspension arm failure due to dry poly bushes that have seized.

 

Regarding the bolts, I'd recommend investing in a new, high-tensile set and replacing the castle nuts with nylocs - you're likely to lose several "concours" points, but nylocs are much easier to work with !

I used loads of silicone spray on them. Not sure it quite it's effectiveness was though. I used copper grease on the upper bushes and then realised after. For red brake grease, any preferences? I have some Textar Ceratec that's designed for brakes but it's not red and no idea if it's safe on rubber.

 

Came in a tube like this.

[SiC]

In regards to nylocs, how do you know when they've been done up tight enough?

 

It's easy enough on the castilated nuts as the hole lines up and is capable of fitting a split pin through. However with nylocs you have no reference. I can't find any torque settings for the parts either.

[cort16]

Fuck a duck that looks like a battle. Unfortunately you learn to expect this stuff, when working on old cars which can sometimes make it slightly more depressing .

[Guest Hooli]

Looks like great fun*

 

Reminds me of when I replace both lower arms on my Midget, on those they contain the spring pan in a triangular plate. First thing I had to do was recut all the threads in the new arms as they were full of powdercoating..

[SiC]

The MGB is kinda similar to the Midget, except the pan + arms are separate and disconnectable. Unfortunately that usually means rusted and solid bolts - especially being on the underside and prone.

 

Even though this has been a bugger of a job, I guess it wasn't too bad as I didn't have to cut anything and could have been much worse. Nothing that brute force and a mallet couldn't overcome. I'm pretty sure this may be the first time it's been disassembled since the factory. The track-rod ends are most definitely stuck on the arm though and will require a bit more work if it ever needs replacing.

 

I really don't know what to do about that lower kingpin bolt tightening up too far though. I'm not happy leaving it like that even with a nyloc.

[Guest Hooli]

Is the kingpin clamped properly? I mean does it look like the clamp needs to be overtightened? or are the sides of the clamp too thin & causing the issue?

[SiC]

I'm really not sure. Looking through my pictures I can't find any of it before hand. However I'm pretty sure it was fine before disassembling. I'm wondering if the end caps fell off when I was putting it all back together for the fourth time.

 

Liz, my wife, came back after being out all day.

"Have you been out in the car yet?"

I had to admit it was more broken not only how I left it last night but also before the weekend.

[Guest Hooli]

Well at least she knows where you are, no need to worry your out and having to fight the flange off with a shitty stick.

[busmansholiday]

Welcome to my world, I spent a fair time over last winter swearing at the the lower suspension system on the roadster. I was lucky in some ways as I dropped on some bits on fleabay and also bought several handfulls of UNF nuts and bolts from the local industrial fasteners supplier for a few quid. This meant I could chuck anything that was slightly shite into the skip.

The problem with castilated nuts is that you have to tighten them to a set torque but if they don't line up, which usually they don't you have to either tighten more or slacken off, neither is a great idea. With nylock you tighten and forget, just make sure there's a small amount of thread at least protruding beyond the end of the bolt otherwise an eagle eyed tester will fail you as the bolts are technically insecure if there's no thread visible at the end.

 

With new bushes it's sometimes necessary to overtighten just to get them to seat correctly. Release the nuts, have a cuppa and try again. If they will not tighten to the correct torque, the bolts could be stretching due to age.

 

All torque settings should be in the Haynes manual, if not the web or my BL workshop manual will have them.

[SiC]

I've checked both Haynes and the Workshop manual but both don't give torque settings for the a-arm. Well it might but the part names it gives for the torque settings don't exactly match the parts diagram names.

 

The current brokenness doesn't help my thoughts on it given that I've been laying on the floor for a day and a half, so I'm aching all over and tired. All for achieving breaking it!

[SiC]

Debating on what parts to buy to replace/fix it at the moment. I'm pondering about just buying everything new to replace all the bits on the front lower suspension and using Polybushes too.

 

I'm really wanting to just get this thing flipping working and actually usable. One of the reasons I used these bushes is because it was cheaper than poly. I still need to rust proof the underside before winter hits too. However I've blown my budget again this month now just getting the bits to get it on the road. I still need to dump around another £100 or so on a rustproofing kit to protect the vunerable bits before the winter hits.

[busmansholiday]

Just had a look and I cannot find the torques for the pivot arm (technical name for the bit the wishbone arms fit onto) but I think I tightened mine to somewhere between 40 & 70 lb Ft (Haynes page 202).

 

You can buy complete kits to replace all the lower suspension bits from the owners club, or probably MGB Hive or even Moss. Had to do this on mine. Check fleabay out as well.

 

Wish I lived nearer, I'd bob down and comisserate with you, I've been in your situation more than once over the years.

[Sigmund Fraud]

For red brake grease, any preferences?

 

Any decent brand would do, I use Comma because they're decent quality, easy to find and fairly cheap. Ceratec is a fairly different compound, I'm not sure it's really safe for rubber and I personally only use it as anti-squeal paste on brake pads.

 

 

It's easy enough on the castilated nuts as the hole lines up and is capable of fitting a split pin through. However with nylocs you have no reference. I can't find any torque settings for the parts either.

 

The alignment of castle nuts with their bolt is no indication that the correct torque has been reached - Mr.busmansholiday's response above is spot-on.

 

Perhaps this document will be some help regarding torque settings for the old B ?

[SiC]

Well it was definitely well above 70lb-ft! I was using a proper 70s snap-on breaker bar, pulling hard enough to start lifting the car. I did a quick test at 70lb-ft, as that's what I had my torque wrench set to for doing the wheel nuts up and it clicked instantly. As the castellated nut wasn't tightened up enough for a split pin to fit, I gave it a few more pulls to try and get it tighter. This is when the breaker bar was really starting to bend...

 

I was aching and fed up at this point, so resorted to the impact driver. Which is what I think damaged the thread. Either that or because it was so darn tight.

[coalnotdole]

I'm not an MGB Expert, But are you working to torque?

 

Strikes me that the inner A arms have been overtightened,

 

Also worth checking have you got all the washers that came off? Are they the correct thickness. ie not excessively rusty.  Are the V8 Bushes the same diameter as the standard ones once pressed into the wishbone?

[SiC]

Any decent brand would do, I use Comma because they're decent quality, easy to find and fairly cheap. Ceratec is a fairly different compound, I'm not sure it's really safe for rubber and I personally only use it as anti-squeal paste on brake pads.

 

 

 

The alignment of castle nuts with their bolt is no indication that the correct torque has been reached - Mr.busmansholiday's response above is spot-on.

 

Perhaps this document will be some help regarding torque settings for the old B ?

According to my phone, I've downloaded that doc before. Not sure where they got their figures from though, as I don't think they're official.

 

The names are also difficult to decipher.

Front Suspension Fasteners

Front shock absorber bolts: 43 to 45

Brake disc to hub: 40 to 45

Brake caliper mounting: 40 to 45

Bearing retaining nut: 40 to 70

Cross member to body: 54 to 56

Shock absorber pinch bolt: 28

Wishbone cross bolt: 28

Anti roll bar link: 60

Spring pan nuts and screws: 22

Stiff nut to crossmember mounting bolt: 44 to 46

King pin to wishbone - lower fulcrum: 45

King pin to damper - upper fulcrum: 40

King pin trunnion (nut on top of king pin): 65

 

On the above, for the a-arm, I can only guess it's maybe the "wishbone cross bolt"? Either way, I'm pretty sure I did it up way, way above that.

[Sigmund Fraud]

I'd also make it the "wishbone cross bolt", and 28lbft sounds reasonable.

 

Interestingly, there doesn't seem to be much agreement on the internet, some sources are along the lines of "just do them a bit tight, doesn't really matter", others recommend specific values that are far higher than 28lbft (Moss suggest 50lbft with polybushes).

[SiC]

So yeah, I'm pretty sure I've overtightened them then - my impact driver (not wrench) is rated for 120lb-ft plus me forcing it with a breaker bar. Maybe even stretching that bottom swivel pin bolt too. Just surprised if I tightened that enough to get it roughly half a centimeter longer?

 

I'm not sure whether to redo it with Polybushes or just replace the a-arm and continue to use the V8 bushes. I'm not convinced they're fitted correctly. I mean they're in and roughly in the middle, but the guts are splurged out the ends.

 

Just removing them to replace it with Polybushes could be "fun".

[PhilA]

Re the alternator, you can crimp a 25 Watt (and from memory somewhere in the region of 50-100 Ohm) resistor in parallel with the dash IGN light that'll keep the alternator charging if the light burns or stops making good contact.

 

Phil

[SiC]

Re the alternator, you can crimp a 25 Watt (and from memory somewhere in the region of 50-100 Ohm) resistor in parallel with the dash IGN light that'll keep the alternator charging if the light burns or stops making good contact.

 

Phil

Yeah I had considered that.

 

Bulb is 2.2w, so at 14v (2.2/14)= ~160mA - call that 200mA for a margin.

14v/0.2A = 70Ohms.

Heat dissipation = (0.2A²)*70Ohms =  2.8Watts.

 

So something like a 80Ohm wire wound resistor at 25Watts has plenty of heatroom for not getting frightfully hot and burning up without getting into thermal dissipation. One like this: http://www.ebay.co.uk/itm/25W-Golden-Aluminium-Load-Resistor-Wirewound-Various-Values-High-Quality-New-/122180980450

 

It would also allow to use an LED as an indicator. Because alternators need a reasonable current flow through the bulb to get the field coil started up, usually an LED on its own isn't sufficient. My suspicion on the problems my alternator has could be that either the bushes are hanging up or worn and maybe the stator is dirty. 

 

As its a genuine quality* Lucas original part from the 80s, I'm tempted to rebuild it rather than replace. I'd just need to find a way to change out the bearings without a press though.

[tooSavvy]

I still need to dump around another £100 or so on a rustproofing kit to protect the vunerable bits before the winter hits.

If you have no cash/spent out/car likely to languish on the drive...

 

Wilko/poondland 10/40 5L is 6.99 + old wallpaper brush

 

... Rinse Drive!!

 

 

TS

[SiC]

If you have no cash/spent out/car likely to languish on the drive...

 

Wilko/poondland 10/40 5L is 6.99 + old wallpaper brush

 

... Rinse Drive!!

 

 

TS

Sounds like one of those ideas that seems great when you do it, but when you next come back and have to work on the car, will forever regret that choice.

[busmansholiday]

This may be a long post but hopefully will be helpful or at least put your mind to rest on the problems with the front suspension bushes. 

 

When I first started putting spanners on cars, several decades ago, my farther would always be onto me not to over tighten any nut or bolt. He'd explain that I'd either strip the thread on one bit or the other or stretch the bolt beyond it's design so it could possibly fail at some future date.  As he did his military service in the mid to late 1940's as an air frame fitter in the RAF and after de-mob he worked in metallurgy for the rest of his life, he knew what he was talking about. As a matter of fact, do you know why the wheel wrench that's supplied by the car manufacturer is such a small piece of shite?.  Basically because if you use it to tighten up the wheel nuts, it's almost impossible for your average person to put that much force onto it that it would damage the nuts or studs, unless they are complete dicks and put a scaffolding bar on the end of it.

 

With the suspension pivot arm it looks like you have ripped the threads out of the nut as the pictures seem to show the thread on the pivot arm is OK.  This should be good news as replacing a nut is a sight easier and cheaper than the pivot arm.  MOSS should stock them, but get nylock UNF nuts, not castilated ones. I cannot remember what size thread they are but you need to run a die down the thread on the pivot arm to clean it / ensure it's still good enough to accept the new nut.  If you haven't got a tap and die set Machine Mart do them (VAT free shortly), you need one with UNF threads such as Clarke CHT302 24-Pce Tap & Die Set. I usually run a tap or die down all nuts and bolts I fetch off that look slightly manky, it helps reassembly.

 

Reassemble the suspension and tighten the new nuts to a max of 50 lb/ft.  In the case of the wishbone system on the MG, the nut you damaged isn't there to stop the suspension falling apart, that's impossible due to the design.  In fact it will even work without these nuts.  The nuts are there to compress the bushes and put some tightness into the suspension. The more you tighten them, the more the bushes compress and the stiffer the suspension becomes.  Mentioning bushes, I still find the best way of assembling them is to use copious amounts of washing up liquid. It doesn't need to be Fairy, the cheap shite we all buy from Aldi /ASDA etc will do.  It has the advantage of being cheap (unless using Fairy), it comes out of the wife's housekeeping budget not you precious car fund, doesn’t damage the bushes (imagine what it could do to your hands if it did) and no matter how much you use, it’ll all wash off the first time you go out in the rain.

 

Take the car a run over some typically shite UK roads then check all the torques when you get home. Have a cup of tea, or a beer to celebrate.

 

As for the alternator, I’m glad you have some gremlins in your MG as well. As it was such a nice day yesterday, and with the wife out all day with her cousin at a food festival down at the nearby Heritage centre, the dog and I decided to take the roadster out for a thrash.  It didn’t feel quite right, then I realised the reason was that the seatbelt wouldn’t retract properly.  When I got back I squirted it with WD40 and gave it a bash with a hammer, but surprisingly it didn’t cure the problem.  Dismantling didn’t show anything odd initially but then I spotted something between the webbing and the lock bar across the rear ratchet system.  Prising it out with a screwdriver, image my surprise, and as a Yorkshireman joy, when first a 1p coin, then a 2p coin popped out, followed by the belt retracting correctly.  How and when the gremlins managed to put the money in there I don’t know, but I’d like to public thank them for their generosity !

[tooSavvy]

SALT to thicken it.... Washhy liquid is a No No 4evva, in my book...

 

Other opinions may vary

 

*car washhy up doby suddso has a glycerine to make it 'creamy' dribbleable = No SALT!!

 

TS

[SiC]

This may be a long post but hopefully will be helpful or at least put your mind to rest on the problems with the front suspension bushes.

 

When I first started putting spanners on cars, several decades ago, my farther would always be onto me not to over tighten any nut or bolt. He'd explain that I'd either strip the thread on one bit or the other or stretch the bolt beyond it's design so it could possibly fail at some future date. As he did his military service in the mid to late 1940's as an air frame fitter in the RAF and after de-mob he worked in metallurgy for the rest of his life, he knew what he was talking about. As a matter of fact, do you know why the wheel wrench that's supplied by the car manufacturer is such a small piece of shite?. Basically because if you use it to tighten up the wheel nuts, it's almost impossible for your average person to put that much force onto it that it would damage the nuts or studs, unless they are complete dicks and put a scaffolding bar on the end of it.

 

With the suspension pivot arm it looks like you have ripped the threads out of the nut as the pictures seem to show the thread on the pivot arm is OK. This should be good news as replacing a nut is a sight easier and cheaper than the pivot arm. MOSS should stock them, but get nylock UNF nuts, not castilated ones. I cannot remember what size thread they are but you need to run a die down the thread on the pivot arm to clean it / ensure it's still good enough to accept the new nut. If you haven't got a tap and die set Machine Mart do them (VAT free shortly), you need one with UNF threads such as Clarke CHT302 24-Pce Tap & Die Set. I usually run a tap or die down all nuts and bolts I fetch off that look slightly manky, it helps reassembly.

 

Reassemble the suspension and tighten the new nuts to a max of 50 lb/ft. In the case of the wishbone system on the MG, the nut you damaged isn't there to stop the suspension falling apart, that's impossible due to the design. In fact it will even work without these nuts. The nuts are there to compress the bushes and put some tightness into the suspension. The more you tighten them, the more the bushes compress and the stiffer the suspension becomes. Mentioning bushes, I still find the best way of assembling them is to use copious amounts of washing up liquid. It doesn't need to be Fairy, the cheap shite we all buy from Aldi /ASDA etc will do. It has the advantage of being cheap (unless using Fairy), it comes out of the wife's housekeeping budget not you precious car fund, doesn’t damage the bushes (imagine what it could do to your hands if it did) and no matter how much you use, it’ll all wash off the first time you go out in the rain.

 

Take the car a run over some typically shite UK roads then check all the torques when you get home. Have a cup of tea, or a beer to celebrate.

 

As for the alternator, I’m glad you have some gremlins in your MG as well. As it was such a nice day yesterday, and with the wife out all day with her cousin at a food festival down at the nearby Heritage centre, the dog and I decided to take the roadster out for a thrash. It didn’t feel quite right, then I realised the reason was that the seatbelt wouldn’t retract properly. When I got back I squirted it with WD40 and gave it a bash with a hammer, but surprisingly it didn’t cure the problem. Dismantling didn’t show anything odd initially but then I spotted something between the webbing and the lock bar across the rear ratchet system. Prising it out with a screwdriver, image my surprise, and as a Yorkshireman joy, when first a 1p coin, then a 2p coin popped out, followed by the belt retracting correctly. How and when the gremlins managed to put the money in there I don’t know, but I’d like to public thank them for their generosity !

Yeah I totally agree that the a-arm fixings have been overtightened and probably weakened. I needed to tighten them up tight though to firstly get the split pin through but also to stop it untightening as the arm moved up and down. Even at 60lb-ft odd, without the split pin in, moving the arms up and down caused friction on the washer which caused it to move. With a nyloc, I'd be worried that it'd be slowly undoing this but still.

 

But then like you said it shouldn't matter too much - as long as the pan bolts stay attached.

 

I also agree with tooSavvy that washing up liquid isn't the safest thing for bushes, given how much it can make untreated steel rust! I'll just get some red grease for next time. Or I'm just thinking of just getting some decent Polybushes to save myself a lot of time.

 

It's no bad thing getting new a-arms though, as the existing ones had rust and ground in rubber on them. This was probably from where the bushes had enlogated and could let crap in. For Polybushes this could be a problem as it wants to twist around that bit.

 

Hopefully after all this, it will handle much better than it was originally! Not that I've driven it enough to know how it was like originally...

[Noel Tidybeard]

i would've though tighten then loosen to next castlation

[Guest Hooli]

i would've though tighten then loosen to next castlation

 

That's what I've always done.

[SiC]

The way it is supposed to work is that the nut and washer tighten the inner metal sleeve of the bush against the mounting so that the sleeve (and washer/nut) can't move.

 

The movement should come from the flex in the rubber.

 

If the inner sleeve and washer/nut are moving then something is wrong.

 

Ben

If you look at the bushes in this picture, the steel tube ended up set inwards compared to the rubber that has squidged out. I was trying to tighten it up enough to get the washer squishing up to the steel tube, for the reasons you mentioned above. Hence why I was tightening it so much.

 

I do wonder if I might have managed that, but the distance between the steel tube and the castellated nut holes isn't sufficient to get the nut done up enough to get the split pin through.

 

Maybe I did tighten it up enough to fit the washer against the steel tube with a ratchet, but was massively overtightening when trying to get it to the castellated nut hole?