BW-35

[mojan]

Hi,



I have a 1966 Volvo Amazon but since it is equipped with Borg-Warner 35 I thought you might able to help me.

The oil seal shown in picture below is leaking and I want to change it, while the transmission is still in the car. Can someone help me with the procedure?


ibb.co/xCtrGwL






Thank you,

Mojan

[lagain]

Pleased to hear that Volvo used a decent gearbox

That seal, from memory, is very easy to replace as it is a push fit, so ease it out and put in the new one, but before you do that put some kitchen paper on the 'box above it to check for a leak. On mine there was a very small hole, no idea why and it leaked fluid. I put a very short self taping screw in it and no more leak.

You may need to drain the box and if it does not ease out it would mean removing the sump.

[enigmas]

If you don't want to remove the seal obtain a small O ring and fit it over the shaft, then refit the selector lever on the shaft. The small O ring will act in compression between the shaft and lever. This should remedy the ATF weep.

These images may assist.

When I rebuilt this trans I fitted a new shaft seal and it still weeped ATF slightly until this fix.







OR

pick the seal out with a hooked scriber or similar tool. Refit using a socket of appropriate size.

Good luck.

[Phil Nottingham]

It can just be picked out and a new one pushed in if you have small thin double jointed fingers  but try the O ring first.

Leaks through that seal generally worsen if the converter non return valve is sticking that allows the ATF level to rise over a period of standing unused. Run it often eg weekly at least  and it will not happen

[tarnowl]

Jul 23, 2021 12:57:41 GMT Phil Nottingham said:

It can just be picked out and a new one pushed in if you have small thin double jointed fingers  but try the O ring first.

Leaks through that seal generally worsen if the converter non return valve is sticking that allows the ATF level to rise over a period of standing unused. Run it often eg weekly at least  and it will not happen

I often have ATF leaks when the car is left standing.  If I have a ‘sticky’ non return valve to the converter, firstly where do I find it and secondly, how to I stop it sticking?

[Phil Nottingham]

It  is buried inside - I am do not know where. Some reconditioned boxes may not have one or it may not have been replaced

[harvey]

Jul 24, 2021 8:21:25 GMT Phil Nottingham said:

It  is buried inside - I am do not know where. Some reconditioned boxes may not have one or it may not have been replaced

The ball and spring is sandwiched between the valve body casting and the centre plate. It has moved position during the lifespan of the box IIRC. It's supposed to stop drainback on the inlet to the converter, but even if that does work, then thay can drain back through the cooler on the outlet side. There is a valve that can be fitted into the cooler return fitting in the box, as fitted on Stags as OE, but they are rarely seen nowadays. There is someone on this forum that made some, but I won't name him, in case he doesn't want to make anymore. I'll let him introduce himself.