The BroBurban - A 2002 2500 Suburban
- Thread starter fl0w3n
- Start date
Welp, that's certainly one of the oddest things I've come across... but it certainly appears that at some point the mounts were cleanly cut out of the truck. Still makes zero sense given everything else being stock, and no lift was ever on it because the factory cross member is still in place and torsion keys/bolts look like they haven't moved in quite a while.
Anyways... that kinda throws a little wrench in my suspension plants. Down travel is easy to handle, I can throw a limiting strap on it. But, I think it cost around $800 to have new bump stops fabricated on my Duramax since those were cut off as well. I don't want to wreck shocks and be going through them as a wearable item because I'm using them as the limit on up travel... hmm.
Anyways... that kinda throws a little wrench in my suspension plants. Down travel is easy to handle, I can throw a limiting strap on it. But, I think it cost around $800 to have new bump stops fabricated on my Duramax since those were cut off as well. I don't want to wreck shocks and be going through them as a wearable item because I'm using them as the limit on up travel... hmm.
Didn't notice you had posted in my thread, I guess you can ignore my PM then
When I got everything apart, it appeared that the PO had done a small front end refresh at some point, and the idler and pitman seemed newer and in decent condition. I hardly got a single pump of grease into the idler arm before it squeezed some decent looking grease out.
As far as the PISK, I'm sure it would help even in my application, and I didn't mean to imply that it's only for heavy 4wd launches in a diesel. I just am doing things on more of a budget compared to the Duramax I built, plus using a little bit of hindsight/second chance to do something differently. We'll see if that works out in the end :costumed-smiley-007
Thanks!
At this point I have no real opinion of the NP246, since I haven't really used it.
The pump rub issue is an issue all the transfer cases of '00 to I believe '11 1500/2500/3500 GM truck/suv 4wd suffer. The oil pump located inside the transfer case is held in place by groves in the magnesium case housing. The notch "edge" of the oil pump that seats into the housing utilizes a small steel clip to keep it in place, but the oil pump wiggles back and forth over time and just wears a hole in the magnesium case. The pump rub fix is to install a new aluminum oil pump retainer plate and get rid of the stainless steel clip. The new oil pump retainer plate fits much more snugly, and doesn't have a knife edge to wear into the case.
Also, if the case wears completely through, it usually happens on the top side of the case. So oil never actually "leaks" down and drips, giving indication. What usually happens is oil is flung out of the hole during operation, eventually running the transfer case dry, and well no oil=bad/boom. Most of the time it is mistaken as a rear pinion seal leak on the axle, or the axle is covered in oil from the spray while driving.
Here's a picture from the internet showing the factory oil pump retainer, and the "fix" with an aluminum one. Notice the edges being much larger and not knife like. Also notice in my pictures how close it was to wearing through on mine. Same on my Duramax, got lucky on both I caught it in time.
^^+2 only way to check is disassemble? I've not heard this either. Here's a cool right up with a PPE kit.
http://www.dieselworldmag.com/installing-ppe-pump-upgrade-brace-kit-2002-duramax/
Another one:
http://www.trucktrend.com/how-to/transmission-drivetrain/1210-8l-gm-transfer-case-pump-rub-repair/
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http://www.dieselworldmag.com/installing-ppe-pump-upgrade-brace-kit-2002-duramax/
Another one:
http://www.trucktrend.com/how-to/transmission-drivetrain/1210-8l-gm-transfer-case-pump-rub-repair/
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I'm not certain on every model of the transfer cases, but coming from the Diesel side and the ones available in those trucks, yes 2wd still rotates the input shaft and therefore the oil pump and creates this issue. Maybe the issue is more prevalent in the diesel side, because it's pretty common all over the forums there. A guy I work with has also been through two transfer cases on his diesel Chevy because of this. Granted that's almost 300k miles worth.
Yeah there's some good write ups and documentation out there.
For the $100 or less in parts to fix it, I think it's well worth the peace of mind. Now that I've done two of them, I can say it's a bit of a cumbersome job to do alone in a driveway... but both times I've wrestled the transfer case in and out by hand and haven't crushed myself yet haha. Also, on both my Duramax and this suburban, the wear was very evident and clearly needed to be addressed. If the case half gets worth through, there's companies that sell just half the housing for about $250, or if you don't catch it in time and the transfer case shreds itself you'll be stranded and looking at a grand + to replace the whole thing.
As far as only way to check, unless you already have a hole worn through and can feel it from the topside by running your fingers over the area... yeah the only way is to disassemble. I recall seeing a thread or two on the diesel forums where some guys tore it apart after 100k or so miles and saw very little wear... but majority of people do find wear like I did. Again, for $100 in parts I think it's good peace of mind.
Anak
Stranger
I would say there is wear in 2wd operation.
It is the oil pump. The T-case needs that at all times.
It is not a particularly difficult job. You will need some special pliers to get a large snap ring off. I also opted to replace my chain while in there.
Best to catch it in time.
ETA: I also remember the instructions I had stating that it was not necessary to remove the transmission mount in order to remove the T-case. I don't know what transmission/application was originally in mind, but that was certainly not true for my case (4L85e (MN8)). This meant it was also a perfect opportunity to replace the transmission mount. Just another detail to consider.
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Merchant Automotive has the most info and I believe are the ones who created the fix.
According to them, cases affected: GM transfer case(model 136, 146, 246, 261, 261HD, 263HD, 263XHD, 261XHD).
More info and a list of vehicles also here: http://www.merchant-automotive.com/10001-Transfer-Case-Pump-Upgrade-Kit.aspx#productTabs1
According to them, cases affected: GM transfer case(model 136, 146, 246, 261, 261HD, 263HD, 263XHD, 261XHD).
More info and a list of vehicles also here: http://www.merchant-automotive.com/10001-Transfer-Case-Pump-Upgrade-Kit.aspx#productTabs1
rayra
Expedition Leader
Thx for the info, I'm definitely going to have to dig into this. Big fan of preventative maintenance and our '05 Tahoe just passed 180k mi and the '02 Sub just 130k mi. And 'over 90k on our '99 Tahoe. 18yrs of these k1500s and hadn't heard of this. Maybe I just haven't got the affected model cases. Have to make sure.
eta
http://www.silveradosierra.com/transmission/which-transfer-case-rpo-do-i-have-t7685.html
2004 Silverado Z71
Trying to figure out which encoder motor sensor I need
NV246 (RPO NP8) uses sensor 88962315
NV263 (RPO NP1) uses sensor 88962313
The RPO will be on the label in glove box. Pretty sure the 263 is in the HD2500 trucks?
The New Venture Gear Numbering System
The first number is the number of speeds:
"1" = one speed (high range). Example – the NV 136.
"2" = two speeds (high range and low range). Example – the NV 241.
The second number is the strength:
The NV 241 is designated "4" in strength – tougher than the NV 231, but not
as heavy duty as their largest T-cases, which go up to a "7" (eg, NV 273,
for vehicles with a GVW of 17,500 lb).
The third number designates the type of T-case:
"1" = part-time 4WD
"2" = full-time 4WD with an open center differential plus lockable part-time
option – like the Selec-Trac NV 242 of the Jeep Cherokee and D***e Durango,
or the Hummer's NV 242HD AMG.
"3" = electrically shifted.
"4" = not currently used.
"5" = Torsen-type differential.
"6" = computer controlled multi-plate wet clutch, like GM's AutoTrac NV 246.
"7" = GeroDisc – like the Grand Cherokee's Quadra-Trac II NV 247.
"8" = not currently used.
"9" = viscous coupling
-----
Doesn't seem teh RPO codes relate to specific models of transfer case, it's more of a 'class' identity, electric, manual floor shift, two speed etc. Or rather, there's only two common models, RPO NP1 is one model, NP8 is another.
eta
went ahead and crawled under the Sub to find the tag. Metal plate bolted onto the rear face of the transfer case, adjacent to the fill and drain plugs.
Is it possible / probably that the wear thru problem is only getting noticed on very high mileage diesel / HD 'work' trucks? That is isn't manifesting on others because they aren't driven as far / long? Or that aren't getting proper fluid changes?
eta
http://www.silveradosierra.com/transmission/which-transfer-case-rpo-do-i-have-t7685.html
2004 Silverado Z71
Trying to figure out which encoder motor sensor I need
NV246 (RPO NP8) uses sensor 88962315
NV263 (RPO NP1) uses sensor 88962313
The RPO will be on the label in glove box. Pretty sure the 263 is in the HD2500 trucks?
The New Venture Gear Numbering System
The first number is the number of speeds:
"1" = one speed (high range). Example – the NV 136.
"2" = two speeds (high range and low range). Example – the NV 241.
The second number is the strength:
The NV 241 is designated "4" in strength – tougher than the NV 231, but not
as heavy duty as their largest T-cases, which go up to a "7" (eg, NV 273,
for vehicles with a GVW of 17,500 lb).
The third number designates the type of T-case:
"1" = part-time 4WD
"2" = full-time 4WD with an open center differential plus lockable part-time
option – like the Selec-Trac NV 242 of the Jeep Cherokee and D***e Durango,
or the Hummer's NV 242HD AMG.
"3" = electrically shifted.
"4" = not currently used.
"5" = Torsen-type differential.
"6" = computer controlled multi-plate wet clutch, like GM's AutoTrac NV 246.
"7" = GeroDisc – like the Grand Cherokee's Quadra-Trac II NV 247.
"8" = not currently used.
"9" = viscous coupling
-----
Doesn't seem teh RPO codes relate to specific models of transfer case, it's more of a 'class' identity, electric, manual floor shift, two speed etc. Or rather, there's only two common models, RPO NP1 is one model, NP8 is another.
eta
went ahead and crawled under the Sub to find the tag. Metal plate bolted onto the rear face of the transfer case, adjacent to the fill and drain plugs.
Is it possible / probably that the wear thru problem is only getting noticed on very high mileage diesel / HD 'work' trucks? That is isn't manifesting on others because they aren't driven as far / long? Or that aren't getting proper fluid changes?
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Anak
Stranger
My read is that it is a function of miles driven, and yes, the diesels probably are more likely to have racked up more miles. Those who were willing to pay the premium price tag for a diesel were most likely willing to do so because they anticipated getting their money back in fuel economy on account of the miles they planned to rack up.
The pump rub is a result of one lobe rubbing against the case. Unfortunately it is a relatively thin item that constantly hits in one small location. Over time it starts to dig its way in, and if left to its own devices will dig its way all the way through. I don't think fluid changes are going to do much to alleviate the problem. It is an impact, not a rotational wear.
Once you get over 100K miles it is time to start worrying about it. I did my Suburban at 115K. It had not worn through, but it was clearly working on it.
If I get a chance I will start a new thread with pictures and details from my experience, rather than thoroughly hijacking this thread.
The pump rub is a result of one lobe rubbing against the case. Unfortunately it is a relatively thin item that constantly hits in one small location. Over time it starts to dig its way in, and if left to its own devices will dig its way all the way through. I don't think fluid changes are going to do much to alleviate the problem. It is an impact, not a rotational wear.
Once you get over 100K miles it is time to start worrying about it. I did my Suburban at 115K. It had not worn through, but it was clearly working on it.
If I get a chance I will start a new thread with pictures and details from my experience, rather than thoroughly hijacking this thread.
Yeah man looks like it's been cut??? I have some close ups attached so you can compare. I have a 2003 2500 burb so suspension should be identical. I have Sumo super springs for bump stops which are much larger than OE and activate sooner. They are poly and compress up to 50% then become progressively stiffer.
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Would you care to share your opinion of those bump stops? Seems like an interesting product.
It's a good buy and does what is advertised. Bump stops activate sooner for a smoother ride and keeps the truck leveled significantly on corners. The poly foam material allows the bump stop to compress up to 80% then stiffens. I basically had no bumps stops prior so going off drop offs rattled the chassis even with the Fox 2.0 with these those same drop offs doesn't feel like much. I give it a big thumbs up! The best mods to keep the OE ride so far have been the bumps stops and bushings.
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snowblind
Adventurer
It's a good buy and does what is advertised. Bump stops activate sooner for a smoother ride and keeps the truck leveled significantly on corners. The poly foam material allows the bump stop to compress up to 80% then stiffens. I basically had no bumps stops prior so going off drop offs rattled the chassis even with the Fox 2.0 with these those same drop offs doesn't feel like much. I give it a big thumbs up! The best mods to keep the OE ride so far have been the bumps stops and bushings.
I have "GM Performance" bumps I got from the dmaxstore. As i recall they came in a GM bag with official "Performance Parts " Logo. They are the same shape and foam construction as the Sumos you reference but are white/yellow. I think these may also be known as "Z71 Bump Stops"
Here's mine for reference. 2001 Suburban 2500. As you can see I have not removed all the excess Autoride suspension parts yet.
Matt
I have "GM Performance" bumps I got from the dmaxstore. As i recall they came in a GM bag with official "Performance Parts " Logo. They are the same shape and foam construction as the Sumos you reference but are white/yellow. I think these may also be known as "Z71 Bump Stops"
Here's mine for reference. 2001 Suburban 2500. As you can see I have not removed all the excess Autoride suspension parts yet.
View attachment 404538
Matt
They are indeed a GM part, they came out on the 2007+ z71 I believe. I had them on my Duramax, and bought them for this Burb until I realized the lack of bump stops lol.
So I finally got everything back together and driving again last weekend.
I'm not thrilled with how it handles, I think it's partly from the shocks and just from the massive amount of weight over the rear axle compared to my old truck. The steering rebuild was well worth it, however.
I think I improved the oil leak, but didn't fix it entirely. It still doesn't appear to be the rear main, but it seems like something from above the starter is leaking oil down the back of the block/bellhousing.
I still have a few more general maintenance items to check off the list, but I can't wait to start getting to the fun stuff... I think stereo is going to be first because the stock is blown out and weak, and that just won't suffice for long road trips.
I left the work vehicle at home today and took the Burb out, got to tool around for "work" at a massive construction site.
I'm not thrilled with how it handles, I think it's partly from the shocks and just from the massive amount of weight over the rear axle compared to my old truck. The steering rebuild was well worth it, however.
I think I improved the oil leak, but didn't fix it entirely. It still doesn't appear to be the rear main, but it seems like something from above the starter is leaking oil down the back of the block/bellhousing.
I still have a few more general maintenance items to check off the list, but I can't wait to start getting to the fun stuff... I think stereo is going to be first because the stock is blown out and weak, and that just won't suffice for long road trips.
I left the work vehicle at home today and took the Burb out, got to tool around for "work" at a massive construction site.