450SL Tranny issue

[tjohn]

Sorry to post yet another one of these transmission questions, but I read the old threads (around 10 pages worth) and didn't see my exact symptoms. I have a 77 450 SL, around 98K miles. My car, in addition to having the infamous two second delay into reverse, also exhibits the following behavior:

1. On a shift from reverse to drive (but not park to drive) will drop abruptly and heavily into gear with a loud thunk.

2. Usually will not properly drop into gear the first time I select the gear - forward or reverse, makes no difference. I have to slightly rev engine, sometimes two or three times, before I engage into the gear. Once engaged, I upshift without difficulty. On downshifts, sometimes on my first stop after first putting the car into a forward gear, I hear a little flaring noise, as if the tranny didn't get all the way settled in. Once its "settled in" it upshifts and downshifts without a problem.

Fluid is proper height (checked warm, level surface, engine idling in park) and color.

I do have a small leak from the front seal (occasionally see a drop of transmission fluid, usually doesn't even show up on the floor).

Thanks to all you wiser heads out there.

[hill]

My sl had the same problem at 110K and 210K. Both times I had it rebuilt. The last time the bell housing had to be changed because the clearance for the front pump was excessive.

[stevebfl]

Because of the front seal leak I would suggest that the solution should be a rebuild. Chances are that you have an internal leak or as noted a low output front pump. Since it is necessary to remove the tranny to reseal the leak and because it undoubtably is rather old, all the seals should be redone. Its only about twice the labor to do the whole job compared to a proper front pump reseal.

You might want to do a service on it as the only other thing you could have is a plugged filter. By removing the pan you also can view whats in the bottom of it. If there is any clutch material steel or brass the thing should be rebuilt before the significant failure comes.

[tjohn]

Thanks to you both. Steve hit it as usual. The transmission has been restored to at least temporary normal function. I think I'll still get the rebuild, but at least I can schedule it for a more (financially) convenient time.