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Re: T37 automatic reverse/2nd strangeness Posted by Cmyles [Email]  (#1126) [Profile/Gallery]
(more from Cmyles) on Tue, 3 May 2011 09:36:03
In Reply to: T37 automatic reverse/2nd strangeness, Jeff Cullen, Tue, 3 May 2011 08:02:52 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Jeff,
That sounds like either the rear band or the rear drum clutch are being erratically applied. That can be the result of failure of the rear band servo, sticking valves in the valve body or damage to the rear band or rear drum elements. A diagnostic trick would be to drive the car in "1" range and see how it performs. In "1" the car should exhibit "engine braking" or "traction" on deceleration as opposed to the coasting on deceleration you should experience when in "D" range, first gear. That traction effect in "1" is produced by application of the rear band which is also required for reverse. If that band is being applied erratically that would explain why you slip in reverse and lock up in second. Second gear is produced by the application of the front drum clutch and the front (flex) band. If you also had the rear band applied, even partially, while in second the unit would lock up. If the rear drum was being applied, or grabbing, and slipping erratically you would get the same effect. I think it's more likely to be a problem with the band which is why it would be interesting to assess for traction in "1" and no traction in "D" at low speed (while still in first gear).
If you are lucky and the cause is sticking control valves in the valve body you may be able to free them up with fluid flushes and maybe disassembly and cleaning of the valve body. If the rear band is shot or the rear drum or rear band servo are jamming there will be no cure short of complete dissasembly and rebuild. You should also determine that all of the tubes are securely installed. If the pans are bent in from "bottoming" the car that can bend and dislodge tubes and interfere with application of friction elements. That wouldn't cause unintended application or grabbing of a clutch or band, more like poor application and slipping, but maybe you have more than one defect at play.
By all means check the adjustment of the shift cable (not to be confused with the throttle pressure cable). If it is out of adjustment the manual valve (in the valve body) will stop between two intended positions and send mixed signals to the control valves. That will (often in very short order) cause destruction of the planetary gears when the unit tries to run in both second and third gears at highway speed.
Unless flushing and clean fluid free up sticking control valves or adjusting the shift cable cure the condition then it will be necessary to remove the pans and poke around in there.
Hope this helps, good luck.
posted by 198.233....
, Tue, 3 May 2011 09:36:03 <-- Viewing This Message, Tue, 3 May 2011 15:08:48, Tue, 3 May 2011 15:10:31, Tue, 3 May 2011 15:34:57
, Tue, 3 May 2011 18:05:31, Wed, 4 May 2011 10:26:43
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