driveshaft or rear end clunk

[natedogr]

I've done some searching and have a few ideas about where the clunking is coming from but wanted to explain my situation to see if anyone has some input. I just had my lsd installed a few days ago by a local tuner shop (this is my first lsd rear end). The drive home was fine. Then the next day and everyday since if I'm pulling in to my driveway or a parking spot real slow there are clunking noises and I can feel it through the floorboards and seat. When the guy was installing the rear end he let the driveshaft just hang there by the carrier bearing. So the whole second half of the driveshaft's weight was all on the carrier. That doesn't seem like a good thing to do. Could that have jacked it up causing it to clunk like it is? While cruising or hard accel everything is fine. Any help is appreciated.

 

[boostcraver]

What kind of LSD did you have installed? Stock or aftermarket? If aftermarket, 1.0, 1.5, or 2 way? Did you follow the recommended break-in procedure for that particular diff, or did you get out there and boost it hard right away? We need a little more info for an accurate answer, please. Based on what you are describing I'm guessing toward aftermarket. That said, it may be the diff "clunking" on you when you take a slow turn, due to the rear wheels trying to lock together as the lsd does what it's supposed to do. If you have a 1.5 way, it will require a rebuild and resetting of the preload on the clutches in the diff itself to straighten it out/make it better than it is now. Not sure about a 2-way, never messed with one of those. I'm sure there is someone who could explain the technical better than I can, as I'm still learning something new everyday.

As long as they didn't just let the shaft drop under it's own weight once they took it loose, and as long as it wasn't already worn past it's prime use, it should be OK, but I feel you on being concerned about it any way 'cuz I'm that way about my car too

 

[natedogr]

Its not an aftermarket lsd. Its a stock 3.90 I've had. When I left the shop I drove for about 60 miles just normal driving, no boosting or hard pulls. As for dropping the shaft, I'm pretty sure he set it down nicely instead of just letting it fall on its own. I watched a little to start out so he definitely took car knowing I was standing there ha.

 

[boostcraver]

Its not an aftermarket lsd. Its a stock 3.90 I've had. When I left the shop I drove for about 60 miles just normal driving, no boosting or hard pulls. As for dropping the shaft, I'm pretty sure he set it down nicely instead of just letting it fall on its own. I watched a little to start out so he definitely took car knowing I was standing there ha.

If it's stock, is it rebuilt or did you take the loose, sealed pumpkin in there and have them install it and remove the old one? If it was just a whole diff swap, housing and all, it may need to have the diff fluid serviced/changed for a start and see if you still have the same noise. Does it break both tires loose or just one if you rev and side step the clutch/braketorque it past the brakes?

 

[SupraMario]

Jack up the back end and make damn sure all 4 bolts holding the lsd pumpkin are on tight. This clunking happened to me after I installed the 2jz. The bolts will come loose. Loktite should do the trick. I've got my money that that is the clunking.

 

[natedogr]

The whole pumpkin was swapped. Took my old one out and put the new one in. I had brand new lsd fluid put in while they were at it. It wasn't rebuilt but I had the shop do an inspection and they said everything checked out. I've already tested to see if both wheels turn during launches and all and they both do. I'll check the bolts holding it in next. I've got my hand on them and they were tight but that doesn't mean they're torqued down.

 

[metaphysico]

All of your power from the engine to the wheels goes through the diff, think of how much force that is, the bolts have to be very tight. Dont remember the spec at the moment though. Or it could be with the more grip the tires are getting ie having both grip now, you could have blown already worn rear arm bushings.

 

[natedogr]

Yeah thats true. I checked the bolts this morning and theyre all torqued to spec. On my way to work just now i noticed at very low speeds, maybe 5 mph, in neutral if i turn the wheel hard side to side i can hear and feel something banging back and forth. On wednesday im taking it back to the same shop and having them look at everything.

 

[RazoE]

was it the proper fluid? It says LSD fluid only, but it requires a special fluid, mine just gave out because the fluid wasnt the right one and I wanted a new one anyway..

 

[boostcraver]

was it the proper fluid? It says LSD fluid only, but it requires a special fluid, mine just gave out because the fluid wasnt the right one and I wanted a new one anyway..

+1^^^ what he said. I filled mine with standard 80-90 weight GL-5 gear oil after pouring a 6 oz. tube of BG LSD additive in.

 

[natedogr]

I used 75 90 non synthetic lsd fluid. Whats the special kind of fluid it needs?

Ok just found the info. Hypoid gear oil, api gl-5. Which is what boostcraver said he used. Where can i find this stuff? Ive never seen any before at advance or autozone

Ok another edit. Just looked on my lunch break. The fluid i used is gl-5 so i shoukd be ok as far as fluid.

 

[boostcraver]

Just get you some LSD additive and add it to the diff, and you should be ok as far as fluid, but if you don't have worn bushings or something else loose back there, your diff is prolly shot

 

[natedogr]

What kind of additive did you use? I looked earlier and only found one kind and it wasnt BG anything or whatever it was you said you used.

 

[boostcraver]

What kind of additive did you use? I looked earlier and only found one kind and it wasnt BG anything or whatever it was you said you used.

It is called BG LSII diff additive. Here you go:http://cgi.ebay.com/ebaymotors/BG-LSII-Limited-Slip-Axle-Additive-Concentrate-/160531921852

 

[natedogr]

The stuff I found has the exact same description as the BG LSII. Works with gl-5 too. I might give that a go.