Slipping auto - Intermittent loss of drive

HI ALL,
Just started getting a problem with my autobox,??? its a bw65,it mostly all works fine, an occasional delay from 2-3 when cold, but when I select reverse, if I pull away slowly its ok, but if I give it a bit of go, it slips, then engages,but feels like it wants to slip more,so I back off!! is it the front or rear band that needs adjusting ??? or is it something else at fault!!
The box was reconditioned [@£440+oil] about 3yrs ago,I removed and refitted it myself, and has done about 9,000 miles,with one full oil flush change,@£125, by the people who rebuilt it, about 2k ago,because the oil went brown!!
But I always have had the niggling feeling that they only fixed what went wrong with it back then,and did not do a full recon job on it!!!. the warranty given was 12k or 12 months,so with a used everyday, 2-3k annual miles car,it should go on for years!!

Any tips, help, suggestions,gratefully accepted.

Cheers,,,,,, dave
 
Hi Dave, firstly with autos always check the basics first
check fluid level, if ness. top up (don't use dexron fluid)

check the linkage is fitted correctly, adjusted & working as it should

check the kickdown cable in the same way.
Talking about BW35/65.

Now assuming thats all correct remember there are no hard and fast rules to diagnosing autos,there are some tips that normally hold true, loss of forward drive = front clutch, loss of reverse only = rear band, loss of top and reverse, rear clutch.
So as you have a reverse and changing into top problem, it could be rear clutch on the way out.

Having paid what you paid and the mileage you have done, I would have my suspicions about the quality of the overhaul as well.
Not only that, the rear clutch piston seal will be damaged on re-fit without a special installer.
 
Hi Dave,
quite often the fluid going brown points to the clutches inside the box are failing. The linings on the clutch plates inside the box contaminate the fluid, sending it brown.

The brake bands if faulty, will usually cause the box to bang into gear on sellection, or cause rough changes when in D.

This is to the best of my knowledge, does anyone have any other ideas?

Good Luck :)
 
Fluid level/colour is ok,
I usually let it tick over for 5 mins b4 driving off, and if there is a delay in changing from 2-3, I usually pop it into 2 then back to D and it changes up. I try to avoid using reverse if poss,just incase it goes completely!! any other ideas out there ??? ???
 
Hi Dave,

I have the same problem with the 2 to 3 change up when my auto box is cold. But I don't have any problem with reverse though. Does your box suffer with a rough down shift when pulling up at junctions?
 
Morning richard,
All the other changes seem fine, The kickdown doesnt always work,I dont normally use it,but I think its down to the carpets being new and a bit thick!!
I am going to check/adjust the kickdown and both the bands today to see if that helps. ??? not a lot more that can be done with it in really!!
DAVE
 
A friend of mine who knows a bit about the good old 35/65 auto box had a look at mine a little while ago. His diagnosis was that the kick down cable needs replacing, as it rests on the stop before the linkage inside the box has fully returned, thus causing the rough downshift. I want to adjust the brake bands on mine, but I haven't yet found a torque wrench that goes down that low!! :)
 
High pressures (kickdown cable adjustment) will cause a clonk on the downshift to first when coming to a halt.
I assume by "rests on the stop" he means the crimp on the inner cable is resting on the end of the outer cable and the pressures are still too high. If this is the case carefully cut off the crimp and adjust the cable properly.
 
Yeah Harvey, you're right. It is the crimp on the inner cable that is stopping against the outer cable before the internal linkage has fully returned. I must get round to doing this soon. the problem is, I enjoy driving him too much!!
 
Oh yes, the crimp is supposed to be set so that when it just rests on the top of the outer cable, the pressures are right, unfortunately too many people don't know how to crimp it on in the right place to start with. Carefully cut off the crimp and set the pressures on a road test.
 
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