Jump to content
PhilA

1951 Pontiac Chieftain - Gearbox

Recommended Posts

20190816_165528.thumb.jpg.a029175c74e14ad7205e3bc31860e693.jpg

I made Special Tool J-4670 out of some bolts and plywood.

20190816_171053.thumb.jpg.4fb66f040bec95699d571f8fed98e1ce.jpg

Made an attachment for the air line out of a tire valve, trimmed it flat.

20190816_171107.thumb.jpg.6079c0caab46d243713eec0b0dcf4618.jpg

Tried with my little air compressor.

20190816_171121.thumb.jpg.4cae4e53931202ac2f39f9b5990b8a50.jpg

That just blew bubbles.

 

20190816_174122.thumb.jpg.f7aff32f2cfb660d72c48fa8e95db82d.jpg

Employed bigger air compressor, win!

 

That represents the last piece to disassemble. It's all reassembly from here on in (barring taking old bearings out).

 

Phil

Share this post


Link to post
Share on other sites

20190817_122917.thumb.jpg.f7484b6227542e3f4a94701b6ce664c1.jpg

Started today by cutting a groove in the bearings I wanted to remove.

20190817_123323.thumb.jpg.efef9cee06522d4b6251781882e03e1e.jpg

Cold chisel to split it all the way.

20190817_123658.thumb.jpg.bdb51114560b0bd7b76a8f5d28e0b720.jpg

Hammered out flat you can see just how bad this bearing actually was.

20190817_133022.thumb.jpg.afd626f69d2f9833e25984693716e6db.jpg

Removed all the seals and cleaned the grooves they sit in.

20190817_133501.thumb.jpg.9094c6a441f415994849c8bc6fb81aa8.jpg

Rubbed all the sealing surfaces down smooth with 1000 grit because they were a bit fouled with alloy corrosion and dirt.

20190817_141217.thumb.jpg.7d6f6278bf070291c502308f72cc3654.jpg

Refitted the piece with new seals

20190817_144111.thumb.jpg.4beb44a5a76064ce1a4fb7e8fbc51d16.jpg

Fitting the piston was a pfaff, there is a step in the outer case where the outer static band locates, and something needed to be put in to remove the step. I didn't have the correct Special Tool so bits of cut up plastic of the correct thickness were added the piston then settled down into the bore happily.

20190817_145803.thumb.jpg.3e7267972c507a7066abad03ca94ae03.jpg

Back together as much as I can put it for now. Typically in all this I missed one piece which needs to be replaced, a wavy spring washer that sits behind a retainer (that I forgot to pull off before this afternoon).

I think I will get some dry ice to put the bearings into before fitting them, that should help.

 

Phil

Share this post


Link to post
Share on other sites
1 hour ago, Tickman said:

Amazing seeing you just getting stuck in and making actual progress. Then some more progress, then more...

 

First automatic transmission I've ever taken to pieces, ever. Hopefully it all goes back together and actually works afterwards.

The gearbox has seen several fairly significant failures; I'm hoping with this overhaul that the weak points are refreshed and will be good for another 100,000 miles.

 

Phil

 

Share this post


Link to post
Share on other sites

"It does move if you put it in gear and it does select more than one gear. However, I have never driven a car with this type of gearbox before and as such do not have a baseline for its behavior".

 

 

Slightly later model with different valve block but the internals are the same and the shift points are the same.

 

Phil

Share this post


Link to post
Share on other sites

I decided to revisit the governor. Having sat a little while it was again sticking in the bottom of the bore.

 

20190818_164958.thumb.jpg.46e122df10fe91bd105925a1ab1330c3.jpg

The smaller weight on the right does the what-speed-the-gears-change-at pressure.

It must move smoothly throughout its entire range. Getting stuck is not an option.

I lapped the surface that it hits into at a rolling angle and that appears to have remedied the issue.

It now clik clak's happily from end to end, even if given a firm prod. That should help with making the gears actually change. I think it was getting stuck before, would certainly explain the behavior.

Phil

Share this post


Link to post
Share on other sites

20190821_195837.thumb.jpg.b1ea0d6e7a1e5a66fc4f414a55f14db4.jpg

New pieces fitted! New big return spring in the front servo ready to go in.

20190821_200154.thumb.jpg.b87acffd4df6c7e060609ce6bd0796e8.jpg

First, put the opposite end piston in place, then fight with the back end one to get the rings to seat correctly in the bore.

20190821_200206.thumb.jpg.2c26123f4610297351535efb5e282d9a.jpg

Main return spring goes in.

20190821_200213.thumb.jpg.520d93b3be91d02c55aeb9796f0a602d.jpg

Locator hat sits on top and keeps the main spring in place.

20190821_200220.thumb.jpg.657843ba232050208b0100d2ecefad9b.jpg

Smaller booster piston spring sits in the hat. The booster piston gets pressure from the compensation valve, connected to the gas pedal; makes for a more positive gear change when you're accelerating hard and grips the band tighter the more you push down on the pedal.

20190821_200408.thumb.jpg.bab3397a1cf43961b803d695b068fe6d.jpg

The two halves them come together and bolt down.

 

One down, many to go!

 

Phil

Share this post


Link to post
Share on other sites
On 8/10/2019 at 3:38 PM, PhilA said:

I just stopped at AutoZone and they've changed up the transmission fluid they stock. Up until 2 weeks ago, they stocked Dexron-IIe. Now, they've rearranged everything and the oldest type oil they keep is Dexron-III compatible "universal" oil.

 

That made me think. Possibly the wrong oil had been put in, because the seals are rock hard and split like so much cheap plastic, and the only bearings that are bad are the phosphor bronze ones in the hubs. 

 

That would explain why it wore to such extremes.

 

Phil

 

 Hi, Putting Dexron fluid into older 'boxes can finish them off, unless they have Dexron compatible linings, because Dexron is a friction modifier.  So check with the supplier of the linings what fluid to use.

Colin

P.S. I'm sure you know this already so apologies if so.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By Zelandeth
      Well I've been meaning to sign up here in forever, but kept forgetting. Thanks to someone over on another forum I frequent poking me about it recently the subject was forced back into my very brief attention span for long enough to get me to act on the instruction.

      I figure that my little varied fleet might bring you lot some amusement...

      So...we've got:

      1993 Lada Riva 1.5E Estate (now fuel injected, as I reckon the later cars should have been from the factory...).
      1989 Saab 900i Automatic.
      1987 Skoda 120LX 21st Anniversary Special Edition.
      1985 Sinclair C5.
      2009 Peugeot 107 Verve.

      Now getting the photos together has taken me far longer than I'd expected...so you're gonna get a couple of photos of each car for now, and I'll come back with some more information tomorrow when I've got a bit more time...

      Firstly...The Lada. Before anyone asks - in response to the single question I get asked about this car: No, it is not for sale. Took me 13 years and my father's inheritance to find the thing.



      Yes, it's got the usual rusty wings...Hoping that will be resolved in the next couple of months.







      Next, a proper old Saab. One of the very last 8 valve cars apparently, and all the better for it. I've driven two 16v autos and they were horrible - the auto box works sooooo much better with the torque curve of the 8 valve engine. Just wish it had an overdrive for motorway cruising...






      Next up a *real* Skoda...back when they put the engine where it belongs, right out the back. In the best possible colour of course...eye-searingly bright orange.





      Seat covers have been added since that photo was taken as it suffers from the usual rotting seat cloth problem that affects virtually all Estelles.

      Then we have possibly the world's scruffiest Sinclair C5...



      Realised when looking for this that I really need to get some more photos of the thing...I use it often enough after all! We have a dog who's half husky, so this is a really good way of getting him some exercise.

      Finally - again, I really need to take more photos of - we have the little Pug 107.



      Included for the sake of variety even if it's a bit mainstream! First (and probably to be the only) new car I've bought, and has been a cracking little motor and has asked for very little in return for putting up with nearly three years of Oxford-Milton Keynes commuter traffic, before finally escaping that fate when my housemate moved to a new job. Now it doesn't do many miles and is my default car for "when I've managed to break everything else."

      I'll fill in some more details tomorrow - I warn you though that I do tend to ramble...














    • By dome
      This evening I venture forth into hitherto unknown lands (Kirkintilloch) to collect my latest acquisition.

      Which, naturally, has issues.

      I have purchased my first line of defence.



      Which appears to have antigravity properties

      More will follow this evening...
    • By davehedgehog31
      I've had various threads on the go for different collections this year, but thought I'd condense my threads into one manageable thread to document my ham-fisted tinkering.

      At the turn of the year I was driving a nice, dependable, modern 2011 Peugeot 407 and no other vehicle. It was nice enough, but boring as feck. I'd bought it after a series of disastrous heaps in the awkward age bracket of being new and valuable enough to worry about but old enough to be fucked. The 407 was just too new, too bloated and dull. I had a hankering for old metal, my Mineral Oil withdrawal pangs were strong.

      From January I started looking, there were eBay bids, missed reserves, wasted trips from Gumtree and other such nonsense. I happened on an automatic Rover 216 GSI with one giffer owner from a year old. The chap was giving up driving at 93 years old and his grandson was moving it on. I bid, and failed. It was in London though, about 420 miles away so I wasn't all that bothered. Of course when he offered it to me for my losing bid after the winning buyer was a no show I said yes. I was on the Megabus down to that London overnight for about £15. I hung about in Liverpool Street station like a mad shivering jakey until my train out to the suburb for my first sight of the new steed. It was battered outside but had been well looked after. A frankly insulting amount of cash changed hands and I was away up the road.

      We had many adventures together, it was dependable and it whet my appetite for interesting old motors again and proved that the very bottom end of the market was navigable if I had the patience to wade through the sea of shit to find the odd pearl.



      The 407 was still on the fleet at this point but I was covering a lot of miles in the Rover, with a long commute though the fuel economy wasn't ideal. When a friend's mother was looking for a new diesel saloon to replace the faithful old Xsara she had a scheme was concocted. I sold the 407 to her and was on the hunt for an interesting replacement.

      When I was growing up my dad had a succession of hopeless shitters, indeed I was brought home from the hospital as a newborn in a brush painted Skoda Super Estelle. The best car he had was a red XUD Peugeot 405 with air conditioning and electric windows. So when I found a 1994 GTXD advertised by someone who could actually compose a car advert in the fashion you would expect of a human being educated to a Primary School level, I pounced.

      Of course I couldn't buy a car just down the road so it was on the train to Birmingham. First class no less. I stayed in an absolute flea pit of a hotel and drove up the road the next day. This was a proper bit of nostalgia and a really practical borderline classic car. It had been fastidiously maintained by the previous owner. Apart from there being a hole where there was once a stereo and the lack of working air con it was a pleasant drive home.

      Given their relative scarcity and how dependable this one has proven so far, it's a keeper, I'd struggle to part with it.



      Two cars just wasn't enough to worry about, so this Citroen C1 was acquired. Pure Aleppo spec. A camel can go for weeks, or months without stopping at a watering hole, the C1 has a similar thirst for Motor Spirit. Man maths were employed and worked out that it would easily* pay for itself.




      There have been further movements, I'll recap them shortly. I should probably do some work.
×
×
  • Create New...