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Old 08-01-2020, 12:52 PM
mgarblik mgarblik is offline
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Default Common Transaxle Leak Points

Good afternoon:
I have a 63 Tempest coming to my shop next Tuesday for a transaxle leak. Owner can't pinpoint the source other than a puddle under the rear of the car. I honestly haven't worked on any auto trans stock type transaxles in these cars. Any particular common leak points or areas I should concentrate on? It was originally a 326 Auto. Now a late model 455 with the same auto trans. It was rebuilt about 40K miles ago according to the owner and it functions great. Just leaks. Thanks for any tips.

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Old 08-01-2020, 05:04 PM
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Ok, a bunch of places, check the shift cable O ring, the speedo cable & drive assembly, the Governor & modulator, trans pan gasket & fill tube. Also with a 63, check the cable that is on the right side that controls the park pawl. There are also diff axle seals (gear oil). There is also a seal behind the torque converter & a seal on the torque shaft at the trans input.

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Old 08-01-2020, 06:12 PM
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That should keep you busy!Tom

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Old 08-01-2020, 06:22 PM
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Could be one or all!!

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Old 08-01-2020, 07:12 PM
mgarblik mgarblik is offline
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Yeeow! Sounds like anyplace two pieces of metal attach together is a leak point. He did say it was red oil, So the diff. section is OK I assume. Thanks for the heads up

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Old 08-01-2020, 07:17 PM
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Quote:
Originally Posted by mgarblik View Post
Yeeow! Sounds like anyplace two pieces of metal attach together is a leak point. He did say it was red oil, So the diff. section is OK I assume. Thanks for the heads up
The trans fluid goes through the diff twice!! There is a gasket between the diff & trans, If that blew out there would be a massive leak while its running. Could also be a bunch of small leaks that make a big mess. You wont know till its in the air. Best bet is to do a good inspection to try & isolate the area, then a good cleaning, run it up to temperature & check again while its running in gear. I get my 61-63 Tempest trans kits from https://www.fatsco.net/

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Old 08-01-2020, 07:33 PM
mgarblik mgarblik is offline
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Thanks for the info. I will check it out Tuesday. If it's something requiring major disassembly or transaxle removal, I will send him back to the shop that built it most recently. If I can change an O-ring, seal or gasket without major disassembly, I will do it for him. I will let you know what I find.

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Old 08-04-2020, 07:43 PM
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I looked at this Tempest today. It would probably be most productive to list what was not leaking! It is definitely leaking fluid in the rear of the car. The dry areas were the torque converter and cap, bone dry, the governor cover was also dry. Just about everything else under the rear was wet with ATF, engine oil, Gear oil, or some combination. The trans fluid really isn't red in color. More of a gray hue to it. It doesn't have a gear oil smell to it so I don't think the fluids are mixing. The right tailpipe, not too far from the dipstick tube had a black crust of burned fluid on it from leakage over time. Starting at the front, the rear of the oil pan had a small leak, the bellhousing and torque tube had some oil in it as well, but not really dripping. The speedo cable and adapter had a little fluid hangong on it as well as the shift cable and manual linkage. I let it idle for 1/2 hour and not a drip on the floor. I recommended de-greasing and cleaning the rear area well and putting some florescent dye in the trans fluid. Then we can re-examine with a black light. Leak diagnosis on a 57 year old car can be difficult.

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Old 08-04-2020, 09:06 PM
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Usually if there is cross contamination of fluids between trans & dif, its trans fluid in the diff.. This thins out the gear oil & diff burns up. Trans fluid should be red. Dye may help locate the leak. After cleaning & degreasing, take it on a drive around town, stop & go traffic. Trans fluid is grey?? Doesn't sound good. One big thing about these is not being able to drain the torque converter when doing a trans fluid change. I have takem 2 different converters to Hughes here in Phx. & had them tighten up the converters, install a drain plug & rebalance. Easy to completely drain & refill.

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Old 08-07-2020, 02:34 PM
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Default Tranny leak

Check the fitting on the transmission pan where the dipstick tube bolts on. It is a pressed fitting and known to leak.

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Old 08-08-2020, 08:51 PM
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Thanks for the tips. I have the Tempest coming back next Friday and I am ready for another shot. He will install the dye and also I have my smoke machine fixed and ready if needed. It's great for finding all kinds of leaks. I can put a little cone adapter on the dipstick tube and fill the entire trans with harmless white smoke. I will let you know what I find. I anticipate multiple leaks.

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Old 08-08-2020, 09:32 PM
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Smoke wont work unless the vent on top of the transmission is plugged,,,,, but that will explain the multiple leaks!

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Old 08-09-2020, 11:17 AM
mgarblik mgarblik is offline
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Good point. I have a selection of rubber plugs to to place over the vents and if not too oily they can be taped. It does prove the vent is clear too which is important. Same goes for using smoke machine as intended on the EVAP system. You have to block the charcoal canister vent to find the actual leak. I have used smoke successfully for small exhaust leaks, engine oil leaks, Evap leaks. Would like to help him if I can. Probably not many of these transaxle cars left on the road.

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Old 08-09-2020, 11:36 AM
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The vent is at the very top of the front of the transmission Don't think you can get a hand up there without dropping down the transaxle.. Same goes for the adjusting point for the low band.. Very hard to get to. The Little Indians chapter of POCI has over 375 members with over 500 members on their Facebook page. There are a lot more out there than you would think!

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Old 08-14-2020, 05:08 PM
mgarblik mgarblik is offline
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I wanted to report back on my second look at this 63 Tempest for ATF leaks. Unfortunately, things never go as planned with a 47 year old car. The owner lives about 70 miles from my shop. By the time he pulled into the driveway, the transmission was slipping badly, not why he was bringing it to me to begin with. He reported when he pulled off the highway exit it began slipping out of nowhere. He said it had been working perfectly up to that point. The unit was rebuilt 16 years ago and has approx 40K miles on it. Well, when I moved it to the rack you needed 1500-1600 rpm's to get it to move. Both in forward or reverse. If you remember from my previous post, I mentioned the fluid had a gray hue to it but didn't smell burnt. Well, it's safe to say whatever turned the fluid gray, whether friction material or metal paste from inside the transaxle, that has finally taken it's toll on it. Just for fun, since it had dye already in it, I did look at it with a black light. The pan was leaking all the way around, the dipstick tube connection to the pan as well. Also both seals where the output flanges for the drive axle shafts locate. Governor, speedo cable area, vent, servo were all dry. Owner has a another complete transaxle and converter he says has a fresh rebuild on it so I guess I will install it for him next week. I have never R&R one of these units so if there are any tips for easy removal and installation, let me know. I have a factory 63 Tempest manual. Only real question I can see is do you like to disconnect the cables from the trans end or the shifter unit on the dash for removal. The manual seems to recommend removing the cables with the transaxle as a unit. I really don't like that idea. BTW, I also smoke tested the unit and it did not produce any results. I think the only way to effectively smoke test it would be with the unit dry.

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Old 08-14-2020, 07:52 PM
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First, drop the torque shaft off the crankshaft per the manual to relieve pressure. I pull the cables off the trans & reinstall. May have to drop the pan to get the shift cable back in position, no big deal. I pull the tires & drums, then unbolt the axles & just pull them back away from the trans/diff assy. If using a trans jack, use a ratchet strap & bind it down tight to the jack. Make sure you drain all fluids first. Can get messy.

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Old 08-14-2020, 08:58 PM
mgarblik mgarblik is offline
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Thanks for the tips. I have read the Tempest manual section 4 several times and there is no mention of needing to drop the torsion bar, (drive shaft), from the engine . It says to support the torque tube and transaxle separately. Will this method work? I ask this because removal of that shaft is apparently an issue according to the owner. This car has a late model 455 engine and some kind of adapter to an aluminum bellhousing and so forth. In addition, one or more of the attaching bolts has some sort of threaded fastener issue and I would rather not open that potential can of worms if I don't have to. If you say it's necessary, I guess I will, but I have a feeling it won't end well. Thank you again. I just re-read and looked at the pictures again. I can see your advice about detaching at the flywheel would make installation much, much easier. I am going to try to detach as you suggested. Great tip.


Last edited by mgarblik; 08-14-2020 at 09:09 PM.
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Old 08-14-2020, 11:36 PM
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Ok, so not a stock system up front. You will have to unbolt the trans from the torque tube and lower it down about 2-3 inches to release the tension on the torque shaft. Then you can slide the transaxle assembly to the rear & lower it down. You will probably have to remove the fuel tank to get room to move the transaxle around. This "Rebuilt transmission" that the customer has?? Is he sure its serviceable? This is a lot of work for something that may not be any good. I would at least pull the trans pan & scope it out to make sure it looks fresh before installing. One thing that always concerns me is on the front of the transmission is the torque shaft coupler. This assembly has 2 splined pieces with 4 hard rubber squares in it with a thin sleeve that holds everything together. These parts are unobtanium!! If they are not in good condition or totally worn out, there will be a hell of a rattle when the engine is shut off. I would pull the front cover off of the old trans & inspect these pieces to understand what I'm talking about. Then, make sure the rebuilt trans has a good set in it.

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Old 08-15-2020, 10:15 AM
mgarblik mgarblik is offline
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Thanks for the additional tips. The replacement transaxle is coming here in the next hour or so. Owner says it was a "no expense spared" rebuild a number of years ago but never installed because the other one was working fine until yesterday, although leaking. I may pull the cover off the old one as you suggested to see what it all looks like inside. I am fairly confident the replacement trans will function. I will need to remove the pan to attach the cables as you suggested anyway. Still leaning toward trying to remove the torsion shaft at the flywheel as you originally suggested. That would allow the shaft to float around some and make installation into the transaxle much easier I imagine. Appreciate the detailed information. I have other modern car work scheduled through Monday so I will probably not get back to this until the middle of next week. I will let you know how it goes.

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Old 08-15-2020, 02:25 PM
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Keith..I've been following this discussion and was wondering about your last comment regarding the "2 splined pieces and 4 hard rubber squares". I'm nearing the point of installing my drivetrain back into the car after a lengthy rebuild and not sure I've seen the items you're describing. Any chance of a more detailed description or pics of the items in question ? I've got several torque tube shafts as well as the pump drive shaft and coupling that it slides into within the front extension housing Just not sure where the 4 hard rubber pieces come into play.
Thanks,
JK

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