LSD Problem, maybe. Someone Diagnose what's going on!

I need help diagnosing a problem, if indeed it is a problem. I'll try to be brief in explaining the issue.

Setup: A few weeks ago I changed my Front Diff, TC, and Rear Diff fluids. I used Valvoline Dino 75w-90 (link). My Rear Diff has the Mechanical LSD, so I used the Trans-X LSD additive (link). In the Rear Diff, I used 3qts of oil + 7oz LSD additive.

Problem: Whenever I make a sharp left turn (usually from a stop), I get a low frequency "whump, whump, whump" sound. I haven't noticed it on right turns or "non-sharp" left turns. Anyone ever had this happen to them before? Is this a problem? or am I just paranoid? Should I just drain the diff and replace with the Toyota 'stealership' additive?

Any and all advice would be helpful. Thanks.

 

Where's Chris when we need him?

 

i've been discussing this with him. he is baffled as well

 

Heres a thread you might find helpful.....appears as though the stuff made by GM is the way to go:


http://www.tacomaworld.com/forum/performance-tuning/74334-lsd-add.html

 

Maybe too much LSD additive. I put a 3.5 OZ tube in mine and i couldnt get a full 3 quarts of gear oil in.

 

Subscribed. I have some Redline 75-90 GL5 gear oil and some Redline LSD additive that I still need to swap out on my truck. Weathers warming up finally so hopefully I can get to it soon.

 

i don't know if it's the same, but when i redid mine, it "stiffened" up the LSD. at lower speeds, when turning, i got that low frequency sound you mentioned, and a very minor vibration. almost felt similar to the carrier bearing vibe when you lift the rear. it made it act almost like a locking diff when i turne on gravel, dirt, or something else slick. I don't mind, as it's been over 15,000 miles since then with no problems, and it seems lo have given me slightly better traction off pavement. if it's just the sound you're getting, i'd say it's probably just the oil/diff additive combination you used, but if it doesn't bother you too much, i think the diff will be just fine. if it does bother you, oil isn't that expensive.

sorry, i know i didn't solve your problem, jsut wanted to let you know i have a similar case with no problems

btw, i'm running synthetic, so that contributes to it a little too.

 

Drive in tight *8* circles in both directions - that's supposed to get the friction modifiers into the clutch paks. Do it several times in both directions.

If this doesn't help and the LSD still seems grabby, then you might need MORE friction modifier.

 

Use dino 80w-90 w/ LSD additive.

 

i will try this in the afternoon

 

I didnt know this. Thanks for the info!!

 

Mine does the exact same thing -- seems to be worse on a left turn. However aside from when I first put it and befor the mixture had a chance to mix I never noticed it before.

I am with the post above -- more modifier might be the fix. Let s know how it goes

 

updates:
1. i couldn't find a place with a big enough parking lot (and empty enough) to do the figure 8's, but i did powerbrake and laid even tread from both tires
2. my diff drain plug had some oil on it (just a few drops), but there was no oil where i normally park, so i wiped it with a rag and we'll see if it is wet later

3. i did, however, make some really tight turns and after that, while making turns, i didn't notice the "whump" sound.
4. also, when i made the tight turns, no chatter, no wheel hop, and didn't feel like it was binding

 

I have noticed this too in mine, but it only seems to be when I first start driving. That or I just don't happen to notice it later in my trip. Although I'm sure I need to change my fluid, just haven't gotten around to it.

TRD mechanical LSD, original fluid, rear end hasn't been touched since I got it new.

 

I have been reading several forums (ttora, toyotanation, etc) and it seems alot of people are having problems with noise in the LSD after they changed the rear diff oil

 

Hey look, It's me. I just had to chime in on this one. I took it in for the rearend noise as the work order states. Next thing I know, their solution was a Rear Spring TSB.... The noise came back after about 500 miles. Maybe the tech took it out back and did a few "8's" with it to quiet everything down. The springs look good though. I will follow up on this because of the interest that others are having the same problem. The other thing that concerns me is that I took off the "fill" plug to make sure the fluid was Okee Dokke and it released pressure similar to someone opening a beer can slowly. I just cracked the plug and a boatload of SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS........came out. I know another member had mentioned that his housing sounded pressurized too. I had 15,000 miles at the time. All pavement driving so I'm not sure if the breather is/was clogged and how it could get clogged going to the Piggly Wiggly and back.

 

^^^ that sounds like the breather is clogged or something.

 

lol, rear diff is making noise.....change the rear springs! makes perfect sense

 

ok, from exhaustively reading online forums, the consensus of toyota truck/suv ppl say that 80W-90 is the way to go even though the manual calls for

$30 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90.