Z71 Jounce Bumpers - Front Suspension

[Ramblejam]

To my knowledge, they're for 2500/3500HD, 1500HD, Suburban 2500, Avalanche 2500.

GM part # 15835667. Purchased mine on Ebay from a GM dealer. Around $20 each with free priority shipping.

Knew of them being on the truck (my OE ones are round, these taper to a point), but never fully realized just integral they were for the suspension to function properly; always thought of them more as a bump stop, which is completely inaccurate.

Super simple to swap out in a few minutes. Subsequently adjusted the torsion bars to where the new bumpers are just barely touching the lower control arms.

Wow -- what a difference! The ride characteristics off-road (or on-road over larger bumps/potholes, etc.) are now completely different, doing a far better job than before!

For the minimal cost and time involved here, I can't recommend them enough!

 

[Bushcoat]

Show us some pictures!!!

 

[Ramblejam]

Old:

New:

 

[locrwln]

My stockers looked exactly the same way and I noticed the same improvement.
.
Jack

 

[rayra]

looks like a design change or a different OEM, I'm finding both styles listed under the same part number. And for around $20 each under all the 'GM parts direct' sort of sites.

It would make sense that the pointed style would act in a more variable / ramping fashion, rather than the rounded bullnosed style.

I bet one could take a hacksaw to the stock rounded ones and get a similar effect. Depends though if the internal hardware attachment is different. Maybe the OP could chop one of his old ones up for 'science'? Maybe its internal bolt head / attachment is wider than the pointed design and hacksawing some of the rubber off would instead cut thru to a void or metal and ruin the whole thing. Would be worth experimenting on the OP's old part, or on a similar part cadged from a junkyard.

 

[Bushcoat]

Cool, I'll have to peek underneath to see what I have.

 

[Ramblejam]

looks like a design change or a different OEM, I'm finding both styles listed under the same part number. And for around $20 each under all the 'GM parts direct' sort of sites.

It would make sense that the pointed style would act in a more variable / ramping fashion, rather than the rounded bullnosed style.

I bet one could take a hacksaw to the stock rounded ones and get a similar effect. Depends though if the internal hardware attachment is different. Maybe the OP could chop one of his old ones up for 'science'? Maybe its internal bolt head / attachment is wider than the pointed design and hacksawing some of the rubber off would instead cut thru to a void or metal and ruin the whole thing. Would be worth experimenting on the OP's old part, or on a similar part cadged from a junkyard.

I'll try to clarify here a bit.

There are two part numbers. They are both OEM GM parts:

15835666 - "Regular" Trucks
15835667 - Z71 Trucks

GMPartsDirect does not use the correct picture on their parts schematics (which may be confusing you).

These come from the factory on Z71 trucks, and are referred to in their brochures as "off-road jounce bumpers".

 

[rayra]

Probably so.
I'll have to go look under our Z-71s tomorrow and see if they were pointed in '02 and '05. I've got to look for a (non- intermediate steering shaft) clunk on the Sub anyway..

 

[Ramblejam]

Probably so.
I'll have to go look under our Z-71s tomorrow and see if they were pointed in '02 and '05. I've got to look for a (non- intermediate steering shaft) clunk on the Sub anyway..

Are you referring to the 1500's in your signature? They use a different setup (than 2500/3500), and these parts wouldn't be applicable.

 

[rayra]

Well you say 1500HD in your opening post, so you are sayign there is yet another different suspension structure, between a 1500 Z71 and a '1500HD' Z71?. That doesn't seem likely.


Anyway, here's the whatever you care to label it on the 2005 K1500 Tahoe Z71

And on the 2002 K1500 Suburban Z71

It seems they are of a similar design and that they are made to flex and give in a manner that works better than a simple rounded bump stop. Which is part of the whole 'Z71' package, anyway. (shrug)

And if there are any targets of opportunity at the auto junkyard later this week, I'll take and post some more photos for comparison / information.

 

[Ramblejam]

Well you say 1500HD in your opening post, so you are sayign there is yet another different suspension structure, between a 1500 Z71 and a '1500HD' Z71?. That doesn't seem likely.

The structure, so to speak, is different between 1500's, and the commonality of 1500HD/2500/2500HD/3500 trucks.

There's no such thing as a 1500HD Z71. Yes, people will put the sticker on, but it didn't come from the factory that way. Additionally, the "off-road jounce bumpers" you see above weren't even made available until after the 1500HD ended production.