BW35 not engaging forward gears after amateur rebuild

Alistair440

New Member
Hi
I rebuilt my BW35 a few years ago then got sidetracked, so only got around to starting the car up recently (it's a Stag I am sorry to admit!). It reverses fine, but it won't move forwards in 1, 2 or D on the selector. Is this something with a simple fix, or am I faced with pulling it back out?

A few details - Car hadn't run since 1979, I bought it partially dismantled, and I found the transmission oil pump cracked (I believe from careless mating of gearbox to engine). I replaced the oil pump as well as the clutch plates, bands, seals etc. Even bought a torque screwdriver to set the front band. I used Vaseline or type F fluid as appropriate on reassembly. I actually found inspiration on this website (I think it was a guy called Andy? Sadly the pictures on the thread vanished between deciding to do the rebuild and actually doing it! By the way, thank you Andy!!). I filled up the transmission as much as possible before start-up (5-6 litres?) and then with the car running it took another 3 or 4 litres, now registers in the middle of the markings on the dipstick with the engine running.

I'm not sure if this is something I should just send off to an expert (no luck finding someone local here in Texas), but I would prefer to avoid that expense if at all possible. Any ideas what I might have done wrong? One thing that just occurred to me - when working on getting the engine started with a friend, he disconnected the kickdown cable, and I don't believe I reconnected it. Would that make a difference?

Any advice or thoughts would be greatly appreciated.
Thanks
Alistair
 
If its been sitting for a long period , the torque converter is possibly drained.
Try starting and leaving in neutral and once warm rock between forward and reverse on engine idle revs. Check the box fluid height on level ground with the engine running.
Worked for me after a year the P6 sat under covers and not started.
 
Loss of all forward drive is normally a front clutch failure. Did you use the correct installers when you replaced the clutch drum piston seals?
 
Thank you for the quick responses.

If I am thinking of the right seals, there are two seals where the warning on Andy's thread was that the seals were easily damaged. I took that part to a professional automatic gearbox repair place and had them install the new seals. I recall that I had to go back because I could see that one wasn't properly seated - I had a spare seal and the second time it looked okay, but who knows. I called that shop this morning to ask their advice and the guy said he wouldn't even look at a BW35 because he hasn't seen one for 20 years, and I wish that I had known that before taking that clutch drum to him! Assuming that is the problem, I guess the box has to come out?
 
PS I think the overhaul thread by Andy that you mention was on the P5 forum. It disappeared because all the pics were on photobucket and they wanted vast amounts of cash to host them (and we know how that ended up), but sadly all those pics were lost and the thread wasn't much good without them.
 
Thanks Harvey. You are right, it was the P5 forum, sorry for any confusion! It was a real shame when the pictures disappeared.

I guess I have to get on with removing the gearbox (really hoped I wouldn't have to!) - any suggestions how to get those seals changed without damage this time?
 
any suggestions how to get those seals changed without damage this time?

Unless you have the proper installers you'll have difficulty replacing the seals withot damaging them, and even with the installers you can nip or roll the seal if you're not careful.
 
Well, that's not good news! Is there anywhere I can get the tools? Anywhere I can see what the tools look like? I seem to remember that Andy had a home made tool, but it's a long time since I looked at that thread.
 
Occasionally the installers come up on ebay, front and rear are different, and there are also different ones for 3 plate and 5 plate clutches. 3 plate ones can be modified to install the 5 plate drums though. Otherwise it's a case of making something.
 
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