1972 P6B Auto (BW35) slipping forward, fine in reverse

M

Malcolm Marshall

New Member
Hi i have bee reviving a P6B ( wasnt running, ruined interior \ locked brakes, door bottoms etc), from what i can tell it was left standing for several years before I got it.. And finally got it in a position where it drove, and was useable. However after running it for about 2 months i have suddenly lost drive. It happened suddenly - i was going along fine. Slowed down for a bend, and then couldnt accelerate out of it.
This is my first Auto box car, so my description might be a bit off, but if this was manual i would say the clutch is worn \ partially engaged. But i was really surpised how this suddenly came about.

I drove the car about 1/4 mile home (only getting uo about 10 mph, trying not to rev too much (i could get a bit of forward movement, but v little). Reverse works fine, (select reverse, engine drops 200 revs, take off brake and your away). put in D or 1 and the revs drop much less (maybe 50) and it doeast creep, and wont pull until I get to 1500, then it just begins to move, and then slips..
Checked oil, and it smells burnt (not surpised it was lsipping on my 1/2 mile trip - but when i looked a week or so ago it was red and didnt smell).

i`m trying to check the fluid level, and it looked like their was too much in there, but after syphoniing some out, i`m not sure , if tI mis- read (told you i was inexperiences with autos - the fluid is like water) and its just some residue in the filler tube running down the spirals in the dip stick.

So based on this i`m assuming the box needs recon \ swap. but before i go down that route i just wanted to check if there was anything more i should text etc. Any advice (what to test, if needed where to get a recon box etc) would be greatly appreciated..
btw i know of the dextron fluid issue, and I did top up with the correct fluid when i first got the car (about a year ago). Just to check it moved etc, before spending too much time money on it.

Nay help greatly appreciated.
 
I vacumed some fluid ouy through the dipstick hole (hose length matched to dipstick) and i am now pretty sre the fluid level is fine now. Tried pulling away etc, and at first it seemed better, but then got worse (as heating up). Although the fluid smelled a bit burned at first, it soon clears and smells normal after a few minutes, so i`m assuming its just begining to fail.
 
After that left it for a while. Now fluid level looks ok, but cant move fwd at all (reverse still fine). So i guess i`m looking at a recon box?
 
Help, It looks llike no garage i can find is willing to change out the box. I can Get hold of a recon box & torque converter ok.

Can anyone give me any advise \ pointers on doing this myself? I have never taken a gearbox out before, but have crawled around under cars doing other jobs for years.
Any advice \ hep would be great. Thanks
 
BW35 means you can remove the box from the bellhousing and converter, then remove those afterwards. Refitting is the reversal of that, but you have to be very careful not to damage the front pump seal when refitting the box to the bellhousing and converter.

If you decide to do it yourself I can give a lot more specifics.
 
Hi Harvey, thanks for the reply. I think Im going to try and get a day off this week so I can try and pull the old box. If I can get the box off without the ball housing, as per your comments. that sounds a lot more manageable (weight wise) on my own. From what I can see the manual seems to only show all in one.

Btwis it normal / worth changing the torque converter at the same time? It's at least the same age etc.
 
Re read through the manual, and I dont know what i was thinking before. Looks like the gbox seperates from the bellhousing in the manual. So i`m going to try that process to remove the current one this week. Thurs \ friday (whatever I can get off work). Thanks for your comments
 
Anyone know how to remove the torque converter bolts. The engine spins when I try to undo these?
Finally got the gearbox off. biggest issue was the stupid dipstick tube. Been tightened up by arnord swartzengger. Managed to force the gearbox off without taking the tube off then when I could get big tools onto it I needed a 3ft cheater bar! - no way I could get the access while the box was still attached.

Slow progress. But progress. Thanks to all that have helped so far.
 
Hi, You need to jam a large screwdriver into the starter rack against the bottom of the block. As far as the dipstick tube goes I made up a short spanner out of 1/8" plate and about 6 to 8 inches long, enough to tighten the nut.

Colin
 
Thanks I'll give that a go. Might have to wait til the weekend now not sure I can get an afternoon off this week and I have been working late recently. I was planning on doing up the dipstick tube with a tap spanner, not sure if that will get it right enough but if not I will have to make up something as you suggest. Again thanks for all the help etc.
 
Help.
Is their a different bellhousing for a torgue converter with a fan?
HI All I got a recon box and converter. The replacement converter has an extra piece of metal on it (Fan) than sits proud of the main body. The gearbox guy commented that my torque converter was a p6, not a p6b. (The old one doesnt have this fan). I can fit the bellhousing over the new converter but I cant turn the engine by hand (can with the bellhousing off). So i assume this is binding somewhere.

So do I have the wrong torque converter or bellhousing ? for a 1972 3500? I cant talk to the gearbox guy until monday.
can I \ Should i cut off the fan? - but then that peob invalidates the warranty.

Any help \ suggestions welcome.

Mal
 
The early BW35 converter with the cooling shroud will only fit the early bellhousing with the cooling vent holes in it, it fouls on the later bellhousing.
 
Thanks Harvey. I'll go back and see if I can get the later converter. Just don't want to wait 8 weeks for my old one to be reconditioned.as the rover is on the drive blocking everything else in.
 
8 weeks to recondition a BW35! Wow!
Also I would be worried by the builders comment of
" your converter is from a P6 and not a P6B"
 
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I think the 8 weeks is more because of the waiting list, and that was the box and converter.. I'll see what he says when I phone on Monday. Tbh the place looked very professional with lots of equipment, and he gave me lots of advice on fitted etc. So hopefully it's a simple mistake.
 
Sorry for the delay in responding. I have been a bit unwell recently. The torque converter was brand new, and the gearbox guy swapped without issue. So now I finally got the box and converter on the car. But ran out of time on the weekend to finish up. So have to just put on the driveshaft and exhaust back on and reconnect the kickdown. So hopefully I can get sorted at the weekend. I guess I need to fill the fluid to the cold line then run the engine /go through the gears, and check fluid properly(hot).
 
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