 |
|
:evil: firstpost
<disregard above>
Like when I’m leaving from standstill especially. The faster I try to take off, the larger the thump, but the LSD definitely works (I’m enjoying the hell out of it). If I shift like butter, I can keep any thumping away while clutching through gears at speed.
Does anyone else know of LSD like this, or can I not ignore thumping?
Any ideas?
Are you sure it’s coming from the diff directly? It could be one of many different things (i.e. driveshaft incorrectly installed, diff incorrectly measured & installed).
Are you sure it’s coming from the diff directly? It could be one of many different things (i.e. driveshaft incorrectly installed, diff incorrectly measured & installed).
No, really, I’m not sure where it is coming from, but previous owner said he had installed a new driveshaft in the last couple of years. Further, looking at the car’s limited records, the owner 2 before me took it to multiple shops for noise/thumping at rear. Again seems to run OK, but a hard start has a definitive thump.
The only reason I ask is in my Bentley manual it says that if there is a thumping noise then the driveshaft was installed incorrectly. I’ll try to get those pages specifically for your reference.
Thanks, man.
I wouldn’t be surprised if the driveshaft was installed incorrectly. I hope it is warm enough to get out in my garage and actually get underneath my new toy. Not sure I’m up for re-installing a driveshaft, but I guess I’ll find out soon enough.
Goes on my short list with:
motor/tran mounts
shifter bushings
Hey, if I have to take off the driveshaft, that should make the shift bushings a breeze, eh?
<I don’t know what I’m saying as I’ve never done anything remotely near this difficult>
:laugh:
Gilles wrote:
[quote]:evil: firstpost
<disregard above>
Like when I’m leaving from standstill especially. The faster I try to take off, the larger the thump, but the LSD definitely works (I’m enjoying the hell out of it). If I shift like butter, I can keep any thumping away while clutching through gears at speed.
Does anyone else know of LSD like this, or can I not ignore thumping?
Any ideas?[/quote]
Did you check the rubber diff bushing? If that is cracked or broken, it will clunk. Had it happen on my 6 series.
-Steve
stevekappy wrote:
[quote]Gilles wrote:
[quote]:evil: firstpost
<disregard above>
Like when I’m leaving from standstill especially. The faster I try to take off, the larger the thump, but the LSD definitely works (I’m enjoying the hell out of it). If I shift like butter, I can keep any thumping away while clutching through gears at speed.
Does anyone else know of LSD like this, or can I not ignore thumping?
Any ideas?[/quote]
Did you check the rubber diff bushing? If that is cracked or broken, it will clunk. Had it happen on my 6 series.
-Steve[/quote]
aka the driveshaft guibo(sp?) They tend to go bad and it will make a thumping noise. I would also check the u-joints as well as make sure your cv’s are in good condition and that your diff has a sufficient amount of oil in it.
good luck,
mike
MikeD wrote:
[quote]stevekappy wrote:
[quote]Gilles wrote:
[quote]:evil: firstpost
<disregard above>
Like when I’m leaving from standstill especially. The faster I try to take off, the larger the thump, but the LSD definitely works (I’m enjoying the hell out of it). If I shift like butter, I can keep any thumping away while clutching through gears at speed.
Does anyone else know of LSD like this, or can I not ignore thumping?
Any ideas?[/quote]
Did you check the rubber diff bushing? If that is cracked or broken, it will clunk. Had it happen on my 6 series.
-Steve[/quote]
aka the driveshaft guibo(sp?) They tend to go bad and it will make a thumping noise. I would also check the u-joints as well as make sure your cv’s are in good condition and that your diff has a sufficient amount of oil in it.
good luck,
mike[/quote]
There is also a rubber bushing on the diff. The diff is held up by two bolts at the front and this circular bushing in the rear of the differential. When that rubber bushing fails, you get a clunking sound.
Don’t forget the center support bearing. Worn or improperly installed will make the driveshaft flop around and make not-good noises.
stevekappy wrote:
[quote]Gilles wrote:
[quote]:evil: firstpost
<disregard above>
Like when I’m leaving from standstill especially. The faster I try to take off, the larger the thump, but the LSD definitely works (I’m enjoying the hell out of it). If I shift like butter, I can keep any thumping away while clutching through gears at speed.
Does anyone else know of LSD like this, or can I not ignore thumping?
Any ideas?[/quote]
Did you check the rubber diff bushing? If that is cracked or broken, it will clunk. Had it happen on my 6 series.
-Steve[/quote]
This is really common on the old Datsuns too. Very easy to do a visual on our cars.
I installed my driveshaft "out of phase" and it thumped exactly as you describe.
My mechanic (the expert) fixed it and the noise was gone.
Carter (the non-expert)
Carter wrote:
[quote]I installed my driveshaft "out of phase" and it thumped exactly as you describe.
My mechanic (the expert) fixed it and the noise was gone.
Carter (the non-expert)[/quote]
I don’t get it - how do you install driveshaft ‘out of phase’ (or: out of phase with what - diff, trany/engine, or the two parts of drvishaft were out of balance between themself))?
How did mechanics fix it - did he rebalanced the driveshaft?
Igor
Igor - I believe what Carter is referring to is that the driveshaft is balanced at the factory as a two-piece unit. If you separate the two halves (at the center support) and don’t put it back together with the dots aligned, it will be "out of phase" and in essence, out of the original balance.
Ed
Thanks, all.
I hope it’s that bushing on back of the diff… sounds easiest. I still haven’t gotten underneath the car, but today when I was doing some careful rev-matching driving the thumping was minimal… actually seemed less than before. I guess I’m just going to keep driving careful for at least another few hundred miles and cross my fingers. I just can’t resist darting around town in the car on weekends.:unsure:
Anybody ever had a thump only in reverse?
My car clunks briefely in reverse. It only happens once in a while and it seems to be only one clunk as opposed to clunk clunk clunk as it rolls. It sound like as the car first moves that is clearing some kind of back lash. As I drive forward and down the road (my car is still licensed) there is no noise.
Could this be in LSD clutches? They are original 18 year old parts that we just have not gotten the “round tuit” for replacement.
Everything else (diff mount, calipers, CV joints) all seem to be solid.
Ideas?
Don
Thumps in reverse and fwd for me… still just thumping when I don’t perform silkysmooth rev-matched clutching. Because I got a track E30, this one with the thump became my roughrustyrunnerstreet E30. I hadn’t thought about it in a long time, but my thumping has now been going on nearly 2 years, the entire time I’ve had the car. At this point, the occasional thump no longer makes me cringe. I think I’ll keep drivin’ 'er 'til something breaks, or it gets louder.
