Who has a lot of experience with the Borg Warner 65 Automatic Transmission?

[tomcolitt]

There's very little I haven't repaired on these cars, but I don't have much experience with the BW65. Here are the symptoms: The car drives and shifts fine in all forward gears, but in reverse it only barely budges backwards. It's hard to describe, but it is almost like the transmission is internally "between gears", fighting against a large resistance. As if the forward and reverse clutches might be pressurized at the same time. Only with a fair amount of engine power the car kind of shudders backwards and it seems like it probably would damage the transmission in short order to keep doing that. I already adjusted both brake bands, but that didn't seem to help much. I took off the drain pan today and there wasn't much crud in there. Some fine friction material and metal particles, but no chunks. The filter was the same. The fluid looked fairly good and didn't smell burned. I checked the Blue books for trouble shooting and the main culprits that seem to apply were the rear brake band and possibly the shift block. My feeling is the shift block could be dirty or a valve stuck or something like that, but I'm afraid that if I clean it out without doing a transmission rebuild, I could loosen dirt and cause more dirt to travel into places it shouldn't be. I want to take it one step at a time. Maybe start with fresh fluid and filter and some TransX conditioner, but I don't expect much from that. After that, maybe flushing the shift block. I don't have a rebuilt kit or even new gaskets for the shift block. Does anyone know where to get those?

Thanks! Tom

 

[twistinglane]

Here is some potentially helpful info from a Rover forum. Experience with fluid changes seemed iffy.
http://www.p6club.com/content/borg-warner-automatic-gearbox

 

[tomcolitt]

Thanks for the link. It looks like I'm already committed to the fluid change since I drained it fairly well. I'm a little confused about the ATF G fluid mentioned in the article. I can't tell for sure if that applies to the BW 35 or the 65 or both. In the BMW Blue books it says (not very clearly) to use ATF Type F or Fa fluid. I don't know if I've seen Type G fluid in the auto parts stores or if that's a British thing.

 

[twistinglane]

Tom,
I suspect you are right that US sold cars used Type F. And that type G was a Borg Warner spec in Britain. And maybe differed by car make?

Hopefully you will get some expert advice.

Here is another link than may be helpful. A repair and fault finding manual for the 65 published by a US transmission outfit.

Good luck! Paul
https://cardiagn.com/borgwarner-6566-transmission-online/

 

[bluecoupe30!]

Hi Tom, I understand this BW65 transmission was also used in Jaguar XJ6s, like 1973-'79. Perhaps other years. Later became the BW66. Perhaps there is a Jaguar specialist in your area. Someone there can probably comment on the transmission behaviour you are experiencing. Keep us up do date! Good luck. Mike

 

[tomcolitt]

Thanks Paul for the very nice manual. The flow diagram on page 66 should be especially helpful to get an idea where to look for problems that could cause the reverse gear not to engage properly. Good point on the Jag XJ6 Mike. Those cars are still found just wasting away here in various places. In fact, I think my neighbor even has one sitting around and probably doesn't need the transmission ...

 

[mosearch]

These guys have "rebuild-kit" parts (though I only bought a new screen and gasket):
https://www.oregonperformancetransm...de=bmw-borg-warner-65-bw65-transmission-parts

I also did an extensive series of drain-and-fill sessions with this "Type F" fluid:
https://www.amazon.com/Mag-910-6PK-...1-1-fkmr1&keywords=Mag+1+912+Type+F+Automatic

It works; can't complain; although it takes a bit of getting used to driving a classic slush-box...just because it's an "auto" does not mean you should not shift.

 

[Honolulu]

This may not be a help, but I got a 2oo2 for pocket change, auto trans, and abused it. Forgive me for I have sinned, but it was a beater when I got it.

One day it ceased to go into reverse. At all. I disconnected the driveshaft with guibo, took off the last cast cover to reveal a small piston that is somehow part of getting into reverse. I had nothing to lose, right? The piston had a barely sensible burr on it, which I honed off with some crocus cloth. Reassembled, alles gut, ready for more abuse. Sold for $500. Carb accelerator nozzle fell into engine for the next owner, something I couldn't have forseen; it was fixed. This was long ago, don't know the later story but thought it might be of some use.

I have a BW sitting on the dirt under my house. Don't know why I'm keeping it, but I do recall it didn't like to go into reverse either. Availability of a four-speed, then a five-speed, made it moot. I doubt it would be worth shipping anywhere across the pond, and the suggestion towards a Jag shop might be most useful IFF the BW doesn't have a similar piston at the back. Lotsa Luck!

 

[bluecoupe30!]

Thanks Paul for the very nice manual. The flow diagram on page 66 should be especially helpful to get an idea where to look for problems that could cause the reverse gear not to engage properly. Good point on the Jag XJ6 Mike. Those cars are still found just wasting away here in various places. In fact, I think my neighbor even has one sitting around and probably doesn't need the transmission ...

Tom, save the BW65 from that Jag. You would be doing your neighbour a favour, and especially his spouse . Mike

 

[tomcolitt]

Today, I completely disassembled the sift block and about 7 or 8 pistons inside. It all doesn't use any gaskets, so I simply cleaned it although really didn't have anything inside that looked concerning. I put it all back together with Type F fluid and a quart of TransX. The sysptoms were pretty much unchanged. Drives great in all forward gears, but when I put it in neutral it still creeps forward for some time. In reverse I have to really overcome some severe resistance and chattering inside the transmission. Once it's free I can easily keep driving in revand erse and there is no more resistance. It's almost like the band or clutch pack for the forward gears holds on for some time and once it breaks loose the resistance disappears. One quick shift into forward gear and the process repeats for the reverse gear. More reading in the Blue book shows that besides the shift block and rear brake band adjustment, possible causes can be seals for the rear servo, bad seating of the fluid pipes (I checked them and seemed good) rear clutch pack. It's probably time to rebuild the whole thing. It looks like the rebuilt kits include all the parts needed and clutch friction discs and brake bands too.

Did the 2002 come with a BW65 too?

 

[bluecoupe30!]

I believe the '02 automatics were first the ZF3HP-12, then in about 1975, the ZF3HP-22.

 

[tomcolitt]

Thanks Mike

I drove the car some more yesterday. The transmission really ran quite nicely except for that binding in reverse. My sense is that maybe the reverse clutch isn't releasing as it should, possibly due to tired springs or damage to the rear clutch pack? Once I break it past the resistance it seems to go freely until I apply pressure to any one of the forward gears and the reverse clutches engage again. I know this is guesswork, but I'm running this by you guys in case someone who knows more about automatic BW transmissions might be able to tell me if I'm on the right track.

 

[tomcolitt]

I think I found the likely cause of my symptoms on page 77 of the excellent ATSG manual that Paul found above: https://cardiagn.com/borgwarner-6566-transmission-online/

Fault Code 9 says: Drive in "N" . Also giving judder or no drive in "R" depending on degree of front clutch seizure.
For this condition the fault key says: "Examine front clutch, support housing and primary sun gear shaft seals.

I think this sounds like an exact match for the symptoms and I already suspected that the clutch pack that's engaged during all forward gears is not releasing (except I thought the reverse gear was controlled by the rear clutch pack and not the front pack, which is engaged in all forward gears and isn't properly releasing.)