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Re: Question for cmyles/tranny experts Posted by Cmyles [Email]  (#1126) [Profile/Gallery]
(more from Cmyles) on Sat, 21 Dec 2019 10:43:56
In Reply to: Re: Question for cmyles/tranny experts, Name Left Blank, Sat, 21 Dec 2019 06:57:38 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Slyde,
Whining, regardless of what gear is engaged, most often comes from worn out bearings.
The fact that the whining may be more noticeable in one gear or another has mostly to do with how the bearing in question is loaded so speed, side loading (accelerating versus decelerating) resistance, etc. play a role in what you hear.
When one of these transaxles has been run without oil to the point of being noisy, exhibiting difficult shifting or inefficient transmission of torque (like unwillingness to move when in gear) that unit is nearly always damaged beyond (practical) repair. In addition to the replaceable bearings in there all the mainshaft gears roll directly on the mainshaft while the counter gear rolls on needle and roller bearings. The hardened journals and surfaces of those gears and shafts are all ruined by spinning without cooling lubricant. They can even heat up enough to gall and become fused together (making disassembly nearly impossible). That fusing of the hardened parts can be what is responsible for the car refusing to move when in gear. The hardened faces of all the gear teeth can also be ruined including the ring and pinion.
All the bearings (except the rear counter gear bearing for >'88 units) are still available. Availability of gaskets comes and goes but the seals are also typically still available. Everything else is hit or miss as parts turn up in warehouses. Early crush collars are NLA but there are good work-arounds for that. For rebuilding I've relied heavily on good used parts for years now.
The spring scale method for setting pinion bearing preload seems to work very well. I check all my set-ups that way. Using an inch pound torque wrench works too but isn't as much fun. After doing lots of these one develops a feel for the correct setting. It's important to use high strength (red) loctite on that big nut and that complicates the preload setting procedure. You have to work fast and get it right, once the loctite sets you're stuck with what you have.
Best case for the transaxle you've described is that it never really ran out of oil, never overheated and the problems described are all due to the failure of one or more bearings as a result of normal, high mileage wear. That could include the pinion shaft supporting bearings or the small needle bearing at the rear of the counter gear. In cases where the pinion bearings are worn to the point that the car actually won't move the final drive gears are almost always damaged beyond further use. Removing the rear cover and having a look as Roger suggests won't hurt a thing but it's pretty hard too see much in there with the unit in the car. If you find gear teeth laying in there or can see other severe damage you'll know something. There's no downside to removing covers and looking inside.
There is also the remote possibility that there has been a failure of the internal shift control mechanism (the parts that move the shift forks and reverse slider gear) resulting in more than one gear being selected at a time. That will keep the car from moving but it's sort of a long shot. It is however one thing that could be seen by inspection after removing the dipstick cover. At this point it's worth doing that. If the reverse slider control has come loose that might be fixed in the car but any other such failure will require gearbox disassembly to fix. Late units (after 1990) have been known to drop one end of the shift fork rod causing shifting problems but not locking up the whole unit. That's not a consideration if this is a 1988 unit.
As Ringo once said, "I've got blisters on me fingers!" so I'm out. Peace!
, Fri, 20 Dec 2019 10:26:57, Sat, 21 Dec 2019 10:43:56 <-- Viewing This Message, Fri, 20 Dec 2019 02:26:56
, Fri, 20 Dec 2019 07:11:37, Sat, 21 Dec 2019 07:25:58
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