BW35 leakage from new pan gasket

gbvona

gbvona

Member
I have gone through my BW35 rather thoroughly and fitted a new pan gasket. As supplied it was composition cork, about 3/32" thick. I sealed on both sides with aviation permatex and torqued the fasteners to whatever the shop manual said. Now I find that I am getting seepage (enough to drip) from the gasket, even though it is squashed fairly tight.

I am also getting drips out of the rear seal, even though it was also installed new. (And yes, I lubed the flange shaft with ATF before fitting.)

Suggestions? Are some gaskets better than others? I hate leaks.


Thanks!

gbvona
 
You are not supposed to use any form of sealant on the pan gasket. Reason being, any small amount that comes adrift on the inside could result in transmission problems.

You also need to ensure that the surface of the pan is completely flat, as the torque applied by the bolts can see distortion, with leaks being the result.

Ron.
 
gbvona said:
Suggestions? Are some gaskets better than others? I hate leaks.
Click to expand...

Don't use any sealant.
Rubber gaskets are available for the sump now.
Make sure the gasket face of the sump is flat.
 
Hi Ron, Excuse me for butting in on this string but I am planning to fit a rubber gasket to my BW35 box in the near future, I had a quick read at the repair manual (the thick white one) and I just wondered if the seal on the selector shaft output is as easy as the book says, i.e. "prise out with a small screwdriver and refit the new one", is there anything I should look out for? presuming I can get a seal.
Best Regards Dave
DAV8
 
DAV8 said:
I just wondered if the seal on the selector shaft output is as easy as the book says, i.e. "prise out with a small screwdriver and refit the new one", is there anything I should look out for? presuming I can get a seal.
Click to expand...

Easy enough to get out, but my advice would be to buy more than one seal, as there's a step on the shaft that turns the new seal inside out if you're not very careful when pressing it back in. Alternatively you could make a sleeve to fit over the shaft and protect the seal.

Get the seals from here:

http://www.jpat.co.uk/Borg%20Warner%2035.pdf
 
Hi Ron, many thanks for the info, sorry to be a pain but I don't suppose you know the actual part part number ?
Best regards
Dave
 
Update on a very long process.

I fiddled with the pan literally for days. Ended up putting it on my milling machine table and using a dial indicator to indicate flat. Got it within about 0.005" (more or less). Remounted. Leaked.

Got a rubber gasket from WINS. Mounted it, about 8 ft-lbs of torque. Leaked.

Miraculously found a spare BW35 tranny (with a 3500S NADA engine no less). Happy happy. Flattened the dimples in the tranny pan with bolt and washers, carefully measured it and tweaked on my milling machine table. It was about as flat as the old one. Mounted it with the rubber gasket. Leaked.

Mounted the newer pan with a composition gasket. Gentle torque (about 5-6 ft-lb, so as not to squeeze the gasket out.) Leaked. Tightened up to 10 ft-lbs. Leaked.

This is where folks are going to start yelling at me. Permatex makes an automatic transmission sealer, compatible with all tranny fluids. I got some. It is VERY viscous. You could try pushing it through the cone dingus that makes a round bead, but I didn't have the hand strength. I smeared a thin coat on the top of the pan, plonked down the (composition) gasket and smeared it on top of that. According to the instructions, you don't need to put it on all surfaces. I was careful to minimize the amount of sealer on the inner edges. Again per instructions I mounted the pan finger tight, let it sit for an hour, then torqued it to about 8 ft-lbs. Almost none of the sealant came squishing out from the joint. Let sit for another 24 hours to cure fully.

FYI It doesn't leak.

gbvona
 
hi there, been there and done that,
tried cork and rubber gaskets , finally ended up fitting the cork gasket and it still leaks, so now just put up with leaks and a large oil drip tray...
Peter
 
lot of effort there but well done for curing leak!. I'd have probably just put a leak pan under car depending. how much leaked!
on the cork gaskets its often important NOT to use lube as this can create a sort of wick effect. though rare. in many cases where such small leaks occur its either one or a combination of things eg distorted part failing to allow even clamping. uneven torqueing down creating same effect. score on a surface .porosity . small particle(s) .damaged part and. even crews /bolts not. being fully home due to crap in threads or bottoming out with crud or wrong length .there are probably more ..just add.
sealers are often used even by garages ( whom ought not to need them) Hylomar being the one I use sparingly. very important to NOT get any excess or odd dribbles/drop within engine ,especially when. tightening down .sealers can form. droplets and get flushed around system causing blockages to. small oil galleries or clog up. strainer on oil pick up .get enough and you have pressure issues and potential major. problem.
 
You must log in or register to reply here.
Back
Top