Odd sensation on acceleration from full stop

[mountie]

( My 2 cents)...... My great / old '88 C2500 was great... I put it on a lift.... I was astonished how easy it was to find loose steering / suspension issues. ( I rebuilt everything )

Put it up in the air. You can easily find problems, by checking the movement, due to everything hanging 'loose' , and other mounts / bushings, etc, can be easily checked.

 

[SRQYukon]

I'm with Mountie. The best way to find anything related to suspension noise is up on a lift. With the ignition unlocked (so the wheels will move) have someone grab a front tire and move it back and forth while you look underneath. That will show worn tie-rod ends, idler or pitman arms. While its in the air you can inspect struts, universals, half-shafts, etc. If all looks good, then its probably internal.

 

[mountie]

I have seen mechanics use a long thin pry bar to see any slight shifting of joints.

Then make a list $$ ..... Works everytime

 

[jyi786]

Update: took it into the shop. Had the most experienced tech take a look.

The front differential bushings are perfectly fine. What is shot?

The motor mounts.

Funny thing is that I did the motor mount test in my driveway, and didn't think I saw much engine movement. But when he did it? It looked like the engine moved way more than I thought. I don't know why I didn't see it. He also explained that's why I feel the thump/lurch when accelerating, and why I'm hearing the clanking noise randomly.

I've set an appointment to get the pinion seal and both motor mounts changed Tuesday.

 

[avalonandl]

I think mine is a worn u-joint.

 

[mountie]

Having your truck up on a lift allows a better view to see movement.

 

[PG01]

Having your truck up on a lift allows a better view to see movement.

Meh, peep through bottom of windshield and youll see that motor move....

 

[mountie]

Meh, peep through bottom of windshield and youll see that motor move....

Yea..... You are right.......

Up on a lift will allow you to actually see if one or both are bad..... ( plus you can wipe off stuff to keep the bottom pretty )

 

[PG01]

Yea..... You are right.......

Up on a lift will allow you to actually see if one or both are bad..... ( plus you can wipe off stuff to keep the bottom pretty )

If it ain’t leakin oil it ain’t a GM.... wait.... i mean harley..... meh....whatever

 

[mountie]

If it ain’t leakin oil it ain’t a GM.... wait.... i mean harley..... meh....whatever

Triumph.......

 

[Doubeleive]

Update: took it into the shop. Had the most experienced tech take a look.

The front differential bushings are perfectly fine. What is shot?

The motor mounts.

Funny thing is that I did the motor mount test in my driveway, and didn't think I saw much engine movement. But when he did it? It looked like the engine moved way more than I thought. I don't know why I didn't see it. He also explained that's why I feel the thump/lurch when accelerating, and why I'm hearing the clanking noise randomly.

I've set an appointment to get the pinion seal and both motor mounts changed Tuesday.

keep an eye on that pinion seal after it is done, if it starts leaking again within a month or two there could be other internal problems, just saying keep a heads up it's cheaper to get it fixed sooner rather than later.

 

[HiHoeSilver]

Update: took it into the shop. Had the most experienced tech take a look.

The front differential bushings are perfectly fine. What is shot?

The motor mounts.

Funny thing is that I did the motor mount test in my driveway, and didn't think I saw much engine movement. But when he did it? It looked like the engine moved way more than I thought. I don't know why I didn't see it. He also explained that's why I feel the thump/lurch when accelerating, and why I'm hearing the clanking noise randomly.

I've set an appointment to get the pinion seal and both motor mounts changed Tuesday.

Gonna use the solid Hummer ones for replacements?

 

[jyi786]

keep an eye on that pinion seal after it is done, if it starts leaking again within a month or two there could be other internal problems, just saying keep a heads up it's cheaper to get it fixed sooner rather than later.

Roger that. It's exactly why I'm doing this right now, so that it doesn't turn into a super expensive mistake later.

Gonna use the solid Hummer ones for replacements?

Precisely. The Hummer H3 ones. Got them ordered on Amazon and shipped for tomorrow delivery.

 

[jyi786]

Update: this story has a happy ending, folks. It was indeed the motor mounts; they were pretty much destroyed. I had the shop replace both mounts and fix the leaking pinion seal. Here are pics of the old ones right before the shop tossed them.



The thump is completely resolved, and there is no clanking when going over bumps any longer.

Many thanks to all you guys for helping me through this, especially @Doubeleive! Major props to you sir!

 

[iamdub]

Update: this story has a happy ending, folks. It was indeed the motor mounts; they were pretty much destroyed. I had the shop replace both mounts and fix the leaking pinion seal. Here are pics of the old ones right before the shop tossed them.

View attachment 229908 View attachment 229909 View attachment 229910 View attachment 229911

The thump is completely resolved, and there is no clanking when going over bumps any longer.

Many thanks to all you guys for helping me through this, especially @Doubeleive! Major props to you sir!

Next time, when you test some motor mounts, you F-IN' TEST THEM! Get on that throttle!

 

[OR VietVet]

I would check the control arm mounts real close. The ball joints of course but maybe a lose or worn out mount where they attach to the frame area. The turn left and over a bump noise contributes to my concerns. Maybe even look to be sure there is no problem at the rack mounts.


Sorry, updated thread while I was typing this in. Congrats on the fix.

By the way I also agree that when checking motor mounts for problems, I have a friend hold ******* the brakes and "goose" the throttle pretty hard to see how much the engine will lift on each side.