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View Full Version : Help with Differential problem on 1957 Transtar (3E7) - twin traction



tim mccracken
04-08-2018, 07:05 PM
Hi folks. Unfortunately my first post here is a cry for help!

I acquired a '57 Transtar last year. No problems for the first months of driving. Then a clunk started from the rear-end when going through a corner with any throttle applied. No noise when coasting through the corner. Yes - this is a TT (Twin Traction) differential. After months of too-much-work and not enough time to look at it myself, I took it to a good local mechanic.

The short of it: tips of gears are chipped and one pin is broken. This is in a Dana 44. it turns out that this is one of few years where the axles are tapered and 19 spline. Talking with Studebaker West there are no new parts for this. While the Dana 44 was used for years, the newer ones have different splines.

Since I will not be taking this off-road, I am thinking that it is a good time to move away from the TT. It also seems like a good time to a lower gear ratio - this one is 4.27.

What are my best options?

I can start the search for another diff or full axle from a 3E7. (Let me know if you have one, or know someone that might!)
Are there any other easy swap-ins?

I throw myself on the mercy of the forum!

Thanks,
Tim

DieselJim
04-08-2018, 08:29 PM
Dana 44 is and have been used by Jeep. Any 4 wheel drive shop should help you out. I have changed the ratio by using a set of gears out of a car. Making sure it is a 44. Changing all parts, including the pinion bearings, cups {races} and shims. Good luck.

RadioRoy
04-08-2018, 09:57 PM
Welcome to the forum, Tim.

Does the truck have overdrive? What ratio were you considering?

StudeRich
04-08-2018, 10:07 PM
Be careful changing the Ratio to a Higher Ratio (Lower as you call it [Numerically]), most of these 1957 & '58's were only 259's, not the more Torquey 289's and the Trucks are Heavy and designed to carry Loads.

So if you have Overdrive and you get too crazy with the Ratio you will have to downshift a lot to Direct, to pull slight grades especially if you Load it, or Tow with it.

A 3.73 MIGHT be a good choice for you, depending on your driving Type and Style, if you don't Haul much.
And, IF you DON"T have Overdrive, it might be time to get it, and leave the Rear Axle Ratio at 4.27 or 4.09.

JoeHall
04-08-2018, 10:24 PM
Depending on the transmission you have, now is a good time to dial the rear gears in for modern roads. If you have a T89 with OD, a 3.73 would be fine. If it is a T89 without OD, a 3.31 would be OK. That is, assuming you do not plan to do much heavy duty hauling with your truck.

DieselJim
04-09-2018, 07:42 AM
Tim, I responded to your message. It would not post. To answer your question, the splines are the same.

tim mccracken
04-09-2018, 11:58 PM
Thanks everyone for the input. A few responses:


Welcome to the forum, Tim.

Does the truck have overdrive? What ratio were you considering?

It does have overdrive. I haven't gotten to the point of figuring what ratio I might want, but happy to get suggestions.


Be careful changing the Ratio to a Higher Ratio (Lower as you call it [Numerically]), most of these 1957 & '58's were only 259's, not the more Torquey 289's and the Trucks are Heavy and designed to carry Loads.

So if you have Overdrive and you get too crazy with the Ratio you will have to downshift a lot to Direct, to pull slight grades especially if you Load it, or Tow with it.

You are on the right track - My engine is a 259.


Depending on the transmission you have, now is a good time to dial the rear gears in for modern roads. If you have a T89 with OD, a 3.73 would be fine. If it is a T89 without OD, a 3.31 would be OK. That is, assuming you do not plan to do much heavy duty hauling with your truck.

My transmission is marked with a T85C-1A. Overdrive is marked R11-G.
When you say "heavy duty hauling", I assume you mean a heavy trailer?
Do I want to be able to fill the bed with wood and drive comfortably? Yes. Might I connect a trailer and move something heavier around town? Yes. A light boat on a trailer - possibly. Do I think I might move 5000 lbs on a car or boat trailer ? Nope.


Tim, I responded to your message. It would not post. To answer your question, the splines are the same.

I am not sure I follow you - the same as what?


Thanks again everyone - the quest continues.

Mrs K Corbin
04-10-2018, 07:32 AM
whatever you do, don't toss the old TT diff, some one may want it for parts, etc.

nels
04-10-2018, 08:10 AM
I doubt your splines are bad. The pin that is broken must be the centering pin, if it’s really broken. These fall out quite often when you pull an axle. What gear is chipped the pinion or ring? Sometimes the ring can be chipped and not really hurt anything as far as noise and drivability. From the symptoms you mentioned it sounded more like your twin traction lubricant was worn out. Its amazing the noise they can make, especially in a turn, when that additive is bad.

DieselJim
04-10-2018, 08:14 AM
I was sent a privet message asking about the axel splines. Thought it was from you. Went back and looked. Was not. Sorry for the confusion. Seems to be my state of mind any more.

tim mccracken
04-11-2018, 07:05 PM
OK - I got a little more info - some of the teeth have sheared off the spider gear(s), and one or both of the cross-pins are broken. Metal has circulated through, so there are impressions on the other gears. It doesn't sound like the internals are salvageable.

So... It seems like options are:
1) All new internals, new diff and custom shafts (because the coarse-spline is no linger available). I asked for a quote. Expect I wont like the $$
2) Find a used differential from the time period with coarse splines. I am thinking an open diff and gear ratio in the 3.73-4.09 range. (any leads on someone that might have?)
3) Find a full hub-to-hub replacement from another 3E7. (any leads on someone that might have?)
4) Find/adapt a full hub-to-hub setup from another vehicle - later Stude, Ford, ?? My preference would be stay stock, or close, but wondering if there is a good option here. I'm not sure how to go about this - any thoughts?

Thanks for the help folks.

DieselJim
04-11-2018, 08:37 PM
I have a 4:09 tt gear set as removed from the rear housing. Has the bearings and shim pack in place. I'm currently in Florida. Won't be home until the 19 th.

Pop's Chariot
04-12-2018, 12:16 PM
I have a 4:09tt rear out of a 57 truck with no hubs or drums. I decided not to put it in my 49 turbo champion truck. I would just like to get my money back out of it. PM if interested I'm in California

DieselJim
04-12-2018, 08:44 PM
I have a 4:09tt rear out of a 57 truck with no hubs or drums. I decided not to put it in my 49 turbo champion truck. I would just like to get my money back out of it. PM if interested I'm in CaliforniaThere you go, Tim. Just change the gear oil, pack the axel bearings, install your brakes, bolt in and GO.

jpepper
04-13-2018, 05:05 PM
The standard Dana 44 used 19 spline axles up through the mid 60's. They then transitioned to larger 30 spline in the late 60's. Your differential case is a "4" series meaning it is made for 3.92 and up numerical ratios. Anything lower than that requires a "3" series case. I think in your truck I would use a 4.09 or 3.92 ratio. You can get parts to repair the TT unit and you can buy a R&P kit which includes all necessary parts. When rebuilding the TT unit replace the bolts holding the two halves together. I use ARP fasteners on them. Parts can be purchased from DTS https://www.drivetrainspecialists.com/index.html , National Drivetrain http://www.nationaldrivetrain.com/ or Motive Gear https://www.motivegear.com/ Your OD ratio is .7 so a 3.92 gives you a final drive of 2.74 and a 4.09 gives you 2.86. 2.86 final drive puts the engine at about 2500 RPM @ 70 MPH depending on tire size. Your 4.27 ratio has a final drive of 2.99 .

tim mccracken
04-15-2018, 01:07 PM
Thanks jpepper. Good info and advice. On the sites you listed, I find rings/pinion kits aplenty, but none of the internal parts look quite like what I see in the Studebaker parts books for the Twin Traction diff. I will paste an image here. I haven't seen anything with a cross pin that looks like those in the image below. Am I missing something?

I'd appreciate any any input on further options. An un-rebuilt, used donor could be inexpensive but potentially risky, and if replacement internal gears/shafts aren't available a potential future problem (please tell me i am wrong on the replacement parts). I've seen some aftermarket units (Auburn/etc), but don't know if there would be complications or quality issues.

Any and all input is appreciated!
https://lh3.googleusercontent.com/XpH81PnBflO1QuxAPEd78IFHJ_rxCqzgTN2vKrR3Ii1yElbgxG133lPg0RMwfwcVR8uQbygIXbGwvcLa nKT5dn2yB8t1QDKew8qjyV2cpxRmh3J36lus6iAX0MqgSkkynCG1sHWiaBYEpn6IZHOx8C5dFNUD25Mx bG2qq2gsyAXMmHsQfyoVGRqsOoN02mSHwywAK-SYiDDYJV6eWEfvVdLp55H1__2XfM1ItSY-a7hwEAhgfwtsGvQmb5KCiCRG8plfb9Yr8wdUtDQQHEjBwJ8yCg8r5SubczRsy_xvB_Idh98W87WBh8Yy k45ezcL4JDFtMK4Cp1A3173CXc8StptD2fYpSkZ67CZ0nQa5gZuzInOz7JVVoCLF-MqkITgFoUbgx50C_inAjRLYj_u04nowepw6OKGJJAYp_BFf37nsJKLBKqgbuAsTBWI0eckdeNFkiMBCv BugEJwDl9XUQvjU2SioU9nSV3VY_91QQ_uCjVvIoAG1kDjzKV2tcoYskPxsbpqhJ01oy_xTKpsPyyef_ _agGg1MshvvCSBM8pPCoc0L8n8cjk2VSPi6N94cN_BjLtM8p-g41peVog-LZe00r6C8igEb0XmpVwyN=w1920-h729-no

RadioRoy
04-15-2018, 03:47 PM
I would not be afraid of a used one, especially from as good a mechanic as Pop's Chariot. In my experience, differentials are pretty sturdy as long as they have not been run dry.

tim mccracken
04-15-2018, 07:30 PM
Thanks Roy - Pop's Chariot and I are PM'ing.

jpepper
04-15-2018, 09:04 PM
The Studebaker TT unit is a Dana Power Lok two piece unit. They also made a traction lok one piece unit. They are completely different. Nels is correct about the center thrust pin. It is a two piece assembly held together with a spring pin. The spring pin is the Achilles heal and it can fail. Also with enough torque, the separating forces can be greater than the yield point of the bolts holding the two halves together. When that occurs, there no longer is any clamp load and the two halves move/slip. In a short time you will shear all eight bolts. Over the years I have sheared the bolts in both a Dana 44 and a Dana 60. Dana made a Power Lok to fit the 55 - 64 Chevrolet rear end. The same failure occurred there especially in 409 cars. Try this for an internal clutch kit. http://www.drivetrainamerica.com/22233x-dana-44-powr-lok-clutch-kit/?utm_source=google&utm_medium=cpc&adpos=1o2&scid=scplp5439&sc_intid=5439&gclid=Cj0KCQjw8MvWBRC8ARIsAOFSVBXwnB_UXGme5WQs52ZZcfRRxnS08qq1FPid8Vq9hNCD_bAtQQ RUd24aAqWXEALw_wcB
or
https://www.summitracing.com/parts/yga-16151
I am assuming the pinion shafts, differential pinions, and side gears are okay.

acolds
04-15-2018, 09:31 PM
shows difference between units