121 with BW35 auto box - Slipping out of 1st

Hello Everyone
I have an Amazon with a BW35 auto box - keeps slipping out of 1st when i try to pull away. If i pull away really slowly on level ground it is ok (usually) but sometimes i can't even engage 1st without engageing reverse a few times.

The oil is murky and has never been changed. I've had the car twenty years and this has been getting worse over the last 1000 miles. I'm not sure if i adjusted the bands (which apparently can be done from outside) i could save it.

Also, I have the chance to get a BW box from a pall who has a NOS one for a granada mk 1. I was wondering if it would fit? I should think it probably would if i retained my volvo housing - any ideas? If not any ideas where I could find out?

Thanks In avance if anyone can help!
Ian

[Andrew (UK)]

Originally Posted by IanHurrell

The oil is murky and has never been changed.

So change it then ;-)

Andrew

[amazondean]

If the oil is merky it's not just a matter of changing it. There is obviously a problem ie slipping bands. The oil is getting hot for some reason. Probably best to replace the box with a known good one. I think the volvo 240 used the bw 35 as well.

[222s]

If a 240 autobox will fit, does that mean that one of the auto + o/d boxes could be used too?

[jimbolya]

just as a matter of interest i was looking into this: the furthest i got so far was this website which is for the P1800 series, but it details the conversion from a BW35 to an AW70/71

http://216.239.59.104/search?q=cache...&ct=clnk&cd=17 text version

http://www.v1800reg.org/pages/AW70%20CONV.PDF PDF file

[classicswede]

The 240 auto box is not the same. The BW35 can be found in 140's.

[Engineer]

Originally Posted by IanHurrell

Hello Everyone
I have an Amazon with a BW35 auto box - keeps slipping out of 1st when i try to pull away. If i pull away really slowly on level ground it is ok (usually) but sometimes i can't even engage 1st without engageing reverse a few times.

The oil is murky and has never been changed. I've had the car twenty years and this has been getting worse over the last 1000 miles. I'm not sure if i adjusted the bands (which apparently can be done from outside) i could save it.

Also, I have the chance to get a BW box from a pall who has a NOS one for a granada mk 1. I was wondering if it would fit? I should think it probably would if i retained my volvo housing - any ideas? If not any ideas where I could find out?

Thanks In avance if anyone can help!
Ian

Hi Ian, if memory serves me right:

1st in Drive is forward clutch pack only.
2nd in Drive is forward clutch pack forward band.
3rd in Drive is forward clutch pack and rear clutch pack.

1st in lock up select is forward clutch rear band.
2nd in lock up select is the same as Drive above.
Reverse is rear clutch pack and rear band.

Only one of the bands is adjustable from outside and I think it’s the rear one don’t shoot me though it’s been over 25 years since I last re-built one that old lol.

So from your description and assuming box pressures ok and valve block working reasonably well it’s a forward clutch fault or rear band.

UPDATE - I now think the problem is due to the gear change linkage.

The gearbox mounting has perished and the box has moved about an inch from where it should be. So this means the linkage was out of adjustment and could not move the gear selector enough to engage drive properly.

I'm in the mids of renewing the mounting but i did a road test in which i removed the linkage and engaged drive myself on the box with my hand. Ran around the block perfectly. FANTASTIC - was over the moon especially when I had spoken to someone who could get me out my problem for £1200!

I'm still stuck with murkey oil so i plan to drop the sump, clean and refill.

THANKS TO EVERYONE WHO REPLIED.

Information on a 40 year old box that wasn't installed on many amazons is hard to come by.

[amazondean]

Keep an eye on the oil colour on a regular basis. If it is anything other than bright red there must be something wrong with it.

[TomTom]

I'm not sure if this is the case on auto models, but I was told that leaking oil can damage the mounting, so if you are taking the gearbox out it is a good idea to check all your seals as well. This is from memory, so others please correct me if I'm wrong.

Tom