1998 4L60-E Problem

[danc5]

This A4 makes a clunking [rrrrrrrk] noise when manually downshifted from about 40 MPH for engine braking. It also delays the shift slightly. Does second gear lock up a band or a clutch? Is this used for any other gear? Can it be adjusted? I have downshifted it all the time for 4 yrs. There are no codes. It will downshift to first without a noise or extra delay.

Thanks, Daniel

 

[c4c5specialist]

HI there,
What gear are you downshifting to???
3 or 2???
As for theory, your overrun clutch would be what you engage in manual ranges.
If you do not have the noise when leaving the car in D4, I would say that your rear planetary set may have an issue.
The 2/4 band is engaged in 2nd and 4th.
Your 3.4 clutch is on in 3rd or 4th gear.
Your forward clutch is on in all forward gears.
I would suggest more information may be needed.
Any noise in reverse????
Or in any other gear????
Allthebest, c4c5

 

[danc5]

A4 noise when going overdrive to second

Thank you very much for your reply and great information.

I frequently drive in overdrive and shift the lever to second when I need to slow down. This is the only time I hear the noise. It just started and does not now do it in any other gear.

 

[c4c5specialist]

HI there,
I would suggest that you have an issue with your overrun clutch/forward sprag clutch engagement.
This is a very difficult diagnosis over the web, but it seems to me that you may have a problem here.
If you reference the following link, you can see 639-644 is the assembly.
http://www.photohost.org/gallery/showphoto.php?photo=5294
Now, do you have engine braking, or does it seem like it is slipping????
Have you had any other work done to the car???
Allthebest, c4c5

 

[danc5]

Yes I do have engine braking but I think it is a little more dealyed than normal. When going OD to 2nd the overrun clutch locks up and what else happens? I have been told that the overrun clutch locks in 1st and 3rd also and I am not having a problem there.

I have had no work done on the car, 40000 miles and no a4 maitnance at all. stock

 

[c4c5specialist]

HI there,
Yes, the overrun clutch does also engage in 1,3 however the stresses are different in those gears than 2.
Honestly, the transmission should be dropped.
There is something going on that is not very common.
Allthebest, c4c5