Autobox again, again, again

[roedmose]

Last year I had problems with a leaking BW35 and hard shifts. In the winter I replaced the seal at the selector and removed the pan and checked everything. As an extra measure I bought a reconditioned p6-box that stands and waits.
-
I consulted the former owner that told me that the box was professional reconditioned some 20K miles ago and that it shifted hard before and after that ! I also discovered that it had been running on DexronII oil in many years so I changed to the correct Ford-type.
-Now I have 2 situations that are more serious than the leaking and shifting hard. Firstly there was no reverse after 30 minutes slow driving in first. A fast drive using all gears reinstated the reverse. But yeaterday there was only first in forward. Stopping tha car and moving the gear-lever between all gears, also reinstated the rest of the gears. After a longer trip now, the box seem to be shifting better than ever. Have anyone any experience as to whether this is a result of the proper fluid "doing its job", og should I finally take that p6 box down from the shelf and get to work and install it Or have I invented the worlds first self-curing BW-box ?? :-)

Frank, DK

[johnwp5bcoupe]

Frank I will keep an eye on the replies from the experts, my box was reconditioned a few years ago it has never been used I have been reading old posts on the type of oil to use there would seem to be a difference of opinion! perhaps I will get a definitive answer as to the correct type?

[Phil Nottingham]

It may be that the correct fulid has helped - why not just wait & see what happens.

It does souns as though there is some valve/servo sticking though - perhaps try some gearbox reconditioner? I generally think these can make matters worse but at least it will decide the issue either way

As regards John's comment I do not think there was a difference of opinion - early boxes that have not been reconditioned or done years ago must have the non Dexron stuff later recon boxes may need the Dexron ATF but the reconditioner should specify

[roedmose]

I read last year (in the archives I think) about Dexron or not, and when I was about to refill the box after re-sealing it, I found out that I could only buy Dexron-type here in DK. I visited one of the few specialist shops and asked as to use Dexron or not and he said that "Dexron or not" was only a matter of quality - "just use dexron, he said". I did not believe him and finally send an email to one of the oil-manufactors and received a friendly e-mail from one of their technicians. I will quote the answer here and I will make his name/company anonymous, as I have not got any permission to quote it. Nor will I, of cource, not take any responsability. But I believed him, and finally ordered a box full of "Ford type ATF".

Quote start ....... :
>>>>>>>>>>>>
"In the seventies ATF's for passenger cars may be divided into two groups: those that contain friction modifiers (all Dexron ATF's and other modern ATF's) and those that not (only ATF Type F). Friction modifiers are special additives that makes oil more "slippery". Until late seventies there were transmission manufacturers producing transmissions with small frictional surfaces ("Ford-style" transmissions) and manufacturers producing transmissions with large frictional surfaces ("GM-style" transmissions). Ford-style transmissions, like Borg Warner BW35, require a non-friction-modified ATF which produces a characteristic "hard" shift. GM-style transmissions require a more "slippery" fluid to permit smooth shifting without shudder. To avoid excessive slippage and heat build up, GM-style transmissions require larger bands and more plates in the clutch. Using the wrong fluid in either type of transmission will result in poor shift quality and shortened component life. So there is only one good ATF-fluid that performs best in your "Ford-style" Borg Warner BW35 and that is ATF type F!
<<<<<<<<<"
Quote end...........

If we believe this statement BW35's should always use typeF, independend of rebuild or not...

Phil, I have never heard of "gearbox reconditioner". But very few people use auto-boxes over here. Are these product from the ordinary oil-companies or what

Frank

[Phil Nottingham]

Molyslip/Wynns/Slick all do them - many are USA based - try Ebay

The final twist to the oil debate was that new type brake bands if used in recent box rebuilds must have the Dexron additive. So its down to the reconditioner to specify the oil

[johnwp5bcoupe]

Ok Phil the problem is with my box I don't know if the materials used were modern or not? I can't ask the reconditioner I would need a "Medium" so I will go for safety and use None Dextron "Type F"

[Phil Nottingham]

I agree entirely

[jlalexander]

A few notes not sorted out:
- the oil companies making themselves Automatic Transmission Fluids are not that numerous; most of the different ATFs you will find on the market are just "re badged" ones.
-the "ATF F type" is a minimum performance specifications.
-the new friction material used since 1990 (roughly) are asbestos free.
-the reasons for a BW35 rough upshifts after reconditioning can be numerous:
line pressure adjustment , kick down cable adjustment,front & rear brake bands adjustment, incorrect clutch plates dishing sequence, incorrect clutch pack free-play etc....
-a box stuck in one gear usually stands for a sticky governor( by the way how can you drive for 30 minutes in 1st!!!!!! Was it for the "Mobil Non economy Run" ?
I would recommend Texamatic 9330 for a BW35.(I have no shares of the Chevron Texaco Co but it's the brand that I have always been using, and I know that they make their products & have a very good technical support) vamotors.lv/saits/eng/226/Texamatic%209330.html
If you bought a recon box, make sure that the clutches have been oiled for shelf keeping, otherwise you might come across funny problems after fitting it.

[Phil Nottingham]

It looks like the definitive answer then - use Texamatic 9330 for all types is that you are saying?

[johnwp5bcoupe]

The box that was reconditioned was my own it had done 31000 miles didn't have a fault but was done anyway, I hope it will be ok as it has been stored 9ish years is there anything I should do prior to running it appart from filling it with ?? oil

[jlalexander]

I would definitely recommend Texamatic 9330 for BW 35s (whether they be 3FU, 7FU,303, etc...) No additive of any sort should be added. For DGs I would strongly recommend Textrans AS. If you go to an Automatic gearbox specialist, beware that for obvious stock management reasons they might not stock 9330 but would offer you 4291 which is a Dexron II and is not good for BW35. There's nothing that can be done to a box that has been standing on the shelf for 9 years except crossing fingers. The main problem is that clutch disks that have been soaked in oil partly can tend to flake off after a while.If the company that rebuilt your box used good parts I can't see any problem.The problem of reconditioned BW35s is how much you've been charged for the job. Regarding the fact that those boxes are 30 years old and have already been reconditioned once or more, if some hardware parts have to be replaced, it can't be done on a budget basis (£ 280-350 is too cheap) If the company that does the job has not been in business for a long time they might not be familiar with those antiques or would not have S/H 35s that would be used as donors for good hardware bits. I know of a firm in Southampton that used not to strip down the valve bodies, but was dropping them in an ultra wave bath device hoping that it would work!!!!(It didn't of course)

[Phil Nottingham]

You can only try it - leaving boxes "dry" can cause seals to stick and tear and bands to stick to the drums and pull off!

[johnwp5bcoupe]

I may be "doomed" or I might be lucky let's look on the brightside!! the box cost me £375 9ish years ago trade! the guy who did it specialised in Jaguar boxes but as he was a friend of a friend he did my box unfortunately he is no longer with us! I will get some Texamatic 9330 if the worst happens I have a spare box that is still full of clean oil or maybe look into an upgrade of some sort?

[jlalexander]

John, to replace your box, don't follow the WS procedure for the 3.5 Litre which is an absolute technical nonsense.Gearbox MUST be removed with the torque!

[johnwp5bcoupe]

Thanks for that info I did change one in my first P5b I had that would be in 1971! I bought the car with a duff box got a seconhand one and bunged it in didn't have the benefit of a WS manual toooooooo long ago to remember what I did! sold it to a PC plod for cash and a fastback VW which my dad had. I am hoping I will be lucky I will leave the box full of oil for a while without starting the engine, which I hope will be in the next couple of weeks I am keeping my fingers crossed on that one as well.

[roedmose]

jlalexander said:

.....( by the way how can you drive for 30 minutes in 1st!!!!!! Was it for the "Mobil Non economy Run" ?

--
Well, jlalexander. It was driving from church with persons in the back with champagne ;D Through the traffic in town and out along the sea to a fine hotel. I promise that as soon as I had unloaded the passengers, I found the high gear again !