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LH OD Problems - suggestions?

A

aerog

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[Echoing my question from another BBS]

I have a '77 MGB with an LH Type Overdrive with sort of the typical slipping problem I've read about, although a little different:

When the car hasn't been driven for awhile (days, weeks, a couple hours) it's perfect with the OD either in or out - in all gears.

Once it's been driven awhile, let's say 30 minutes or so I'll tend to get a slip in any gear with the OD out - but only until the engine speed reaches a certain point, then the OD clutch "catches" (for lack of a better description) and everything is fine. This also results in the typical problematic "over-run" problem, where the direct-drive doesn't lock and the engine is free to idle down. I also have to add that once the OD's clutch engages there is absolutely no hint of slippage at all. This problem is most evident in reverse. Occasionally it will go into reverse, but when it's bad it slips like mad - not enough gear to go up any kind of incline at all.

With the OD in (either cold or after having been driven) there is no sign of slippage in 3rd or 4th.

The OD is relatively new, although I'm not the original owner so I don't have the exact history on it.

Now the question(s):

(1) The normal remedy or at least TRIAL remedy is to drain the oil, clean the screens and valves, reassemble, and top off the gearbox with 20w50 - sometimes repeating to flush out any Slick-50 someone might have been silly enough to pour in. Has anyone had any experience with the symptoms I've described, and can they suggest whether this is perhaps just an oil problem or a definite sliding-member problem (I'm apt to take the cheap oil-change route just to see what happens anyway).

(2) I've read two different types of oil mentioned, just run of the mill every day quality 20w50 engine oil, and then specifically non-detergant engine oil. Any comments on using either one over the other (I'd hazard a guess non-detergant just to stay away from any additives,but...)



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-- Scott
https://www.aerog.com/mgpage

wavingus.gif
 
Scott --

Sorry I can't help you with the OD problem. I've got the same kind of transmission on my older B. (A retrofit.) But I know nothing about trannies.

So far, my OD works great . . . But as always, I keep an eye on these boards to glean whatever knowledge I can to anticipate future woes.
 
I received this follow up to my LH/OD question:

Richard Day, Didcot, Oxon UK, r.j.day@rl.ac.uk
Scott

I have experienced exactly what you are saying on a 79GT.
The initial "temporary" cure was removal of the the solenoid, clean all filters and drain and fill with 20/50.

The problem then re-occured and has now some 4000mls later been cured by replacement of the o-rings and ball on the solenoid. When you fit the new ball a lite tap with drift and hammer will help seat.




------------------
-- Scott
https://www.aerog.com/mgpage

wavingus.gif
 
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