Vibration or wheel hop?

[RLDaily]

OK Andy, thanks

Semper Fi

 

[RLDaily]

How about this one...Could my rear brakes be cycling because of a short or something?

I'm showing an ABS/Traction Control failure

 

[dadaroo]

I doubt it but pull the 2 EBCM fuses and that will disable ABS, AH, and TC completely. That will tell you what you want to know.

 

[RLDaily]

I'll give 'er a shot

 

[RLDaily]

Would that be fuse #'s 52 & 53

 

[dadaroo]

No, it is Fuse 5 and 52 in the engine fuse box..

 

[RLDaily]

OK, got it

When I do it, what should happen?

Thanks

 

[Hib Halverson]

Ok.
So we have a 2000 which occasionally, under mild acceleration, gives you a rumble strip feeling from the right rear?

Questions:

How many miles on the vehicle?
What does the right rear feel like under moderate-to heavy decel but no braking?
What does the right rear feel like under maximum acceleration but no wheel spin?
If you mildly accelerate while turning, does that affect the symptom?
Your posts about this imply it's something that you feel but can you hear anything when it happens? Buzzing? Clicking?

 

[dadaroo]

OK, got it

When I do it, what should happen?

Thanks

It just disables ABS,AH, and TC to take them out of the equation. If you still have the issue they are not a cause.

 

[Lakotah]

Similar problem

OK, got it

When I do it, what should happen?

Thanks

RLDaily,
I had a similar problem. You didn't mention what brand tires you have and/or are they new? Turned out my problem was with the tires. It started when I replaced the run-flats with Michelin Pilot sports. The tread design they had was a ribbed design that made a slight vibrating sound and feel on acceleration coming from the rear. Changing the tire pressure a pound or two made no change at all. It was something I just put up with until the tires wore down enough that noise and feeling just gradually went away. I might also mention that my C-5 always pulled to the right even after a wheel alignment. Turned out one mechanic switched the front tires, then it pulled to the left. So I had a bad tire in the front and noisy ones in the back. Needless to say I'll never buy Michelin tires again. Hope this helps.

 

[RLDaily]

Appreciate it but if it were tires it would be continual, I can go 20 miles with nothing happening...Occasional means infrequent, sometimes, every now and then, not all the time. The parameters are what the parameters are, the bit about the transmission is interesting especially with my having about 89000 miles now.

The tires are not OEM or run flats and they have at least the 30000 miles that I put on them

I never hear anything when it happens because I'm a retired grunt and city cop and lost a good deal of my hearing 30-40 years ago topped off with a heavy dose of tinnitus

I was thinking axle/cv but it seems that would be continual as well wouldn't it?

 

[LLC5]

Appreciate it but if it were tires it would be continual, I can go 20 miles with nothing happening...Occasional means infrequent, sometimes, every now and then, not all the time. The parameters are what the parameters are, the bit about the transmission is interesting especially with my having about 89000 miles now.

The tires are not OEM or run flats and they have at least the 30000 miles that I put on them

I never hear anything when it happens because I'm a retired grunt and city cop and lost a good deal of my hearing 30-40 years ago topped off with a heavy dose of tinnitus

I was thinking axle/cv but it seems that would be continual as well wouldn't it?

When was the last time you had your rear differential serviced? If it's over 20-30K you may want to change it for maintenance reasons and see if anything changes.

Also, certain road conditions can cause your original post complaint. If you drive over the same roads continuously (like I tend to do), see if it happens in the same road areas. It could be just the road surface.

 

[RLDaily]

As far as I can tell neither the differential or transmission have ever been serviced (I'm the 2nd owner and it had 57000 on it in Aug 2011 when I got it)

The roads I drive on are good to excellent and I've even picked the vibration up on new concrete & asphalt (non grooved surfaces)....Could it be slippage from the rear end?

 

[LLC5]

As far as I can tell neither the differential or transmission have ever been serviced (I'm the 2nd owner and it had 57000 on it in Aug 2011 when I got it)

The roads I drive on are good to excellent and I've even picked the vibration up on new concrete & asphalt (non grooved surfaces)....Could it be slippage from the rear end?

I suppose it could since the LSD does have clutch plates in it, and so does your automatic transmission. It may not be a bad idea to service both (you could do one at a time if you wanted to do a test) as a maintenance only procedure, and see if it cures your issue.

 

[RLDaily]

OK, I'll try the differential 1st, thanks....Time to put my A&P mech skills back to work a bit. What lube would you recommend, the new synthetic stuff?

 

[LLC5]

OK, I'll try the differential 1st, thanks....Time to put my A&P mech skills back to work a bit. What lube would you recommend, the new synthetic stuff?

I use Redline 75W90 High Performance Gear Oil myself with the LSD additive in it. Remember to change the fluid after it is hot to help remove as much of the suspended particulates as possible (true of any fluid exchange), that can take quite s bit of driving first for the diff fluid to get hot. A freeway run if possible should do it. Remember that you are only doing this for maintenance and not for a repair. If it does take care of your problem it will just be a bonus. Good luck with it.

 

[RLDaily]

OK guys an update. The car is 89,800+ miles now

In March I changed the differential fluid (it was the factory stuff) and refilled with Mobile......Drove around for a couple hundred miles but still seemed to have the small problem we've been discussing

A couple weeks ago I tackled the tranny filter & oil (I didn't flush I just drained the pan).
1st - the bottom of the pan looked great, no particles of anything, the oil was slightly brown (but still red) and the magnetic strip just had that slimy stuff, and only a little bit of it
2- getting the filter seal out was a chore but I got er done
3- replaced everything with OEM type stuff (pumping the oil into the trans with the car running and the exhaust and oil are "HOT" was really fun, I recommend it to everyone)
4- Ran the trans through gears while it was still up in the air keeping the oil hot and rechecked the level... A bit of oil came out of the plug just like instructed
5-closed everything up and went for a drive....Trans temp OK

The transmission is shifting better and crisper than ever, vibration or whatever appears gone. I just got back from Joplin MO absolutely no problems and the oil hung around 170-185 or so.

Could funky oil and an old filter cause what I was experiencing? As far as I know there was 89K plus on everything.

Anyway, I do not recommend anyone change their own trans filter unless they really know their way around and are a bit maso to boot.

 

[gmjunkie]

OK guys an update. The car is 89,800+ miles now

In March I changed the differential fluid (it was the factory stuff) and refilled with Mobile......Drove around for a couple hundred miles but still seemed to have the small problem we've been discussing

A couple weeks ago I tackled the tranny filter & oil (I didn't flush I just drained the pan).
1st - the bottom of the pan looked great, no particles of anything, the oil was slightly brown (but still red) and the magnetic strip just had that slimy stuff, and only a little bit of it
2- getting the filter seal out was a chore but I got er done
3- replaced everything with OEM type stuff (pumping the oil into the trans with the car running and the exhaust and oil are "HOT" was really fun, I recommend it to everyone)
4- Ran the trans through gears while it was still up in the air keeping the oil hot and rechecked the level... A bit of oil came out of the plug just like instructed
5-closed everything up and went for a drive....Trans temp OK

The transmission is shifting better and crisper than ever, vibration or whatever appears gone. I just got back from Joplin MO absolutely no problems and the oil hung around 170-185 or so.

Could funky oil and an old filter cause what I was experiencing? As far as I know there was 89K plus on everything.

Anyway, I do not recommend anyone change their own trans filter unless they really know their way around and are a bit maso to boot.

You were probly experiencing torque converter shudder, and yes fresh fluid and a filter usually will fix that if it'd not too bad!

I like to change trans and differential fluid about every 40-50,000 miles