Is This My Imagination or What?

[Gebo]

I had this shudder on take off at 15 mph in my 2005 LS430. Not every time. Very Slight.
Gone at 20 mph. I posed the question here and obviously, it couldn't really be answered in a forum.

Last night I decided, what the heck, let's drain and try a different gear oil. No biggy.
See if a different brand of gear oil would alleviate this shudder.

I changed it out and drove to the dumpsters. About a 10 mile round trip. The shudder
is gone. I stopped and started probably 30 times. No shudder.

Full disclosure, the gear oil that was shuddering was a 75W-110 and I replaced it with
75W-90. Two well known and highly respected name brands.

I ain't gonna tell you what I was using or what I substituted. Not here to bash and get
panties all in wads.

My question is, could that slight shudder have been caused by my differential not liking
a particular brand?

 

[AZjeff]

How old/how many miles on the old lube?

 

[Trav]

All I can think of it it has something to do with the clutches if its a limited slip.

 

[WylieCoyote]

Was this shudder when accelerating in a straight line, or while taking a turn?

 

[Gebo]

How old/how many miles on the old lube?

10K

 

[Gebo]

Was this shudder when accelerating in a straight line, or while taking a turn?

Straight line.

 

[Gebo]

All I can think of it it has something to do with the clutches if its a limited slip.

I'm gonna PM you

 

[Gebo]

Please note.

No shudder until right at 15 mph and gone almost immediately.
Not repeatable but it would do it at least 1 out of 5 times.
Very slight. My wife would not notice.

This car did have the drive shaft replaced a year ago. My mechanic was replacing
the hanger bearing and separated the drive shaft and we could never get it balanced.

 

[WylieCoyote]

If you're sure it's fixed, that's a good thing, but just note, I've never heard of a LSD shuddering while traveling in a straight line. They normally produce clutch chatter while turning, if the required friction modifier isn't present in the oil.

Torque converter was my suspicion. Let us know if it re-appears.

 

[AutoMechanic]

I suppose it could be the fluid maybe. Not too sure though.

 

[Snagglefoot]

Well, you are driving a Limited Slip 430..........

 

[Gebo]

If you're sure it's fixed, that's a good thing, but just note, I've never heard of a LSD shuddering while traveling in a straight line. They normally produce clutch chatter while turning, if the required friction modifier isn't present in the oil.

Torque converter was my suspicion. Let us know if it re-appears.

Well, I ain't sure. I can tell you that. I'll need to drive it a lot more to be completely sure. I'm over 90% confident.

This shudder would not be noticed by most anyone else.

 

[Trav]

Please note.

No shudder until right at 15 mph and gone almost immediately.
Not repeatable but it would do it at least 1 out of 5 times.
Very slight. My wife would not notice.

This car did have the drive shaft replaced a year ago. My mechanic was replacing
the hanger bearing and separated the drive shaft and we could never get it balanced.

Straight line will not cause shudder or chattering with a limited slip. If you notice it returns again I would suspect the shaft or TC.
I cant see fluid making any difference.

 

[Gebo]

Just for the record, it ain't limited slip. I jacked it up and turned a wheel. Goes in opposite direction.

I'll give it some more time. Starting and stopping. Sorta weird....

 

[atikovi]

Maybe the fluid level was too low and your refill got it back to normal.

 

[nascarnation]

Maybe the fluid level was too low and your refill got it back to normal.

Why would that make a differential shudder sporadically?

 

[Gebo]

I was thinking that it might be “borderline”. I really have no idea. I’ll give it some more test drives

 

[atikovi]

Why would that make a differential shudder sporadically?

Not enough lubricant on the gears as it sloshes backwards.

 

[MattPersman]

I have seen this on a couple trucks old fluid just worn out or oxidized etc

It’s not super common but amsoil and or redline hold up very well if you have a fussy one

 

[Gimpy1]

If you're sure it's fixed, that's a good thing, but just note, I've never heard of a LSD shuddering while traveling in a straight line. They normally produce clutch chatter while turning, if the required friction modifier isn't present in the oil.

Torque converter was my suspicion. Let us know if it re-appears.

This !!!a diff issue is noticed when wheel speeds are different, as in a turn, or a whine at speed or during accel or decel. A shudder is usually an issue with the trans.