1988 - 2000 GM OBS Truck and SUV Rear Axle U-Bolts & Anchor Plates Replacement (Chevy & GMC)

[@brandonkahuna1251]

Usually your OBS videos drop right after I just did that same job on my truck. You beat me to it this time, though the parts are sitting on my bench to do this now. Lol! Good video as always! I got to get to mine before long! Really helpful!

[@cruiser1947]

Great video and information . My 1990 GMC is a mess. Its missing the passenger side ubolts and upper and lower plate. Thanks for posting this video.

[@joeg7755]

Again, another excellent video, your attention to details of any subject in video and your write ups are impeccable. Funny, when changing U-bolts as I have done in the past, I would have cleaned axle and brackets, and unless they were totally compromised I wouldn't have paid any more attention to them, I guess just taking them for granted. But you have educated me, I will be looking at EVERYTHING closer in detail from now on. No more taking things for granted. BTW how do you like your induction heater? Is it good quality? Thanks Joe

[@DrShock]

Thanks, I love the bolt buster (the original inductive heat tool). I still have my oxy-acetylene torch setup but haven't pulled it out in years. ;-)

[@RamboBurgers]

Mine are so bad it’s leaking oil out of the axle tubes if I park in a slanted spot. Now I know what to do thanks.

[@gtd6288]

FYI, the GM part number listed for 10 bolt axle spring anchor plate for my 2000 Chevy 1500 when I checked gmpartsdirect is 25761309 for both sides (I assume, since they only list left side on the site.) You have a different numbers listed (15592585 and 15592586). Not sure if they changed it, or there are multiple part numbers going around. I will have to check it for fitment when it gets here. Thanks for the video!

[@DrShock]

This video, and the part numbers, are only for OBS (old body style) C/K trucks. It wouldn't apply _directly_ to the NBS trucks that launched in 1999. So for 2000, yours is an NBS as the OBS 1500 pickups ended in 1998. For 2000 only the 2500/3500 were still being produced as a _classic_ in the old body style. Hence the difference in part numbers you ran into. Technically the OBS 3500 was still produced well into MY2002, but I don't include this year or MY2001 to avoid confusion.

[@gtd6288]

@@DrShock Ah, sorry I missed that. I figured the axles would be same, since they appeared identical. New to GM trucks. They are a bit confusing with how many years and models they had. Thanks for clearing that up!

[@wb5352]

Now I have to look at my truck. Thanks 😢

[@variousrepairs1946]

I wonder if using the pb blaster from the top and bottom of the bolt would make it easier to come off without breaking?

[@DrShock]

I'd say no. The reality is that penetrating oils only go so far with heavy corrosion and compacted road dirt, there's been some other folks who did test videos about that. The only tools that would have avoided the break would have been an oxy-acetylene torch or induction heater. But I strongly suspect we would have ended up cutting them off anyway like the drivers side so ended up just fine imo.

[@duncdunc76]

First I gotta say your vids are Great and have given me some valuable info in regard to assessing my 1994 K2500 6.5 Suburban. So Thanks! One question, why can't you use the passenger side on the driver's side just flipped around? Are all other dimensions aside from the rounded cuts on each side semicircle? Sorry might be a dumb question as im assuming if you could flip them around you would have bought 2 new passengers.

[@DrShock]

Thanks. When I went to collect the OEM parts for this job, I noticed that both the 1500 trucks and the 2500 trucks had a different number for LH and RH sides (all those parts are in the video description btw). Both are still available for the 1500 trucks, but GM discontinued the LH side for the 2500. Knowing how cheap GM can be, they wouldn't have made two different parts if they could have made only one. I believe you could get away with using two RH anchors, but given the axle tube corrosion / pitting I didn't want to chance even a _mm_ of extra pressure and tracked down the correct LH side from a southern bone yard donor.

[@duncdunc76]

@@DrShock Makes sense. And I'm getting a vibe from watching your vids that you like to have the parts as oem and period correct as possible. Not sure if I'm getting the correct vibe on that but if so it would be proper for you to source the correct left hand side with the correct part# instead of putting a right side on the left side. Again, I really enjoy and appreciate your Vids! Thanks so much for sharing your knowledge and skill!

[@DrShock]

I spent a few decades doing GM classic restoration work, numbers matching and back to GM assembly line originality. I only do repair work nowadays and that's mostly what I share on the channel , but I suppose that attention to OEM restoration detail does give off a _vibe_ here and there even on a repair job. ;-)

[@keithcronk7980]

GREAT JOB BTW you got a link FOR URE impact THANK you. I have 2 do mine.

[@patrickjohnson7801]

Maybe put oil on the threads and start with 20 LBS while you're at it might as well remove the bolts that holds on the backing plate, Thay are in the same shape as the u bolts, hit the brakes and around we go.

[@jasonmartindale3171]

So, my u joint broke, put my 97 Chevy Tahoe up on Jack stands and noticed my passenger side u-bolts and plates are COMPLETELY GONE, driver side has only one u-bolt still there. Assuming this is the reason my u joint broke, but you mentioned keeping the drive axle lined up by doing one side at a time. Since i really don't have any anchoring now, how screwed am I?

[@DrShock]

If I ran into this situation, I'd rebuild this area lining up on the _witness marks_ left on the axle tube from the previous anchor plates. Once you get the repairs done, you can take it to a driveline shop where they can do a rear end alignment to dial it in the rest of the way.

[@421CentralIowa]

I still don't understand why there are different left and right side plates. LMC Truck sells only one part that supposedly works on both sides for my C1500, but everywhere else says there's a drivers vs passengers one.

[@DrShock]

LMC is selling the aftermarket part that way because it can "fit" on both sides, but they are _slightly_ different in shape as I showed. Given that GM discontinued one side for the 2500 trucks (you can still get both sides for 1500 trucks) you don't have many options other than going used as I did, or using two of the other side that is still available.

[@421CentralIowa]

@@DrShock I was on GM's parts website and they're acting like they're not available for my 1989 C1500, but I'm going to try to source some OEM ones. Mine are paper thin and the U bolts are about as thick as number 2 pencils at the moment, ha!

[@DrShock]

I put the part numbers for all of the C/K trucks in the video description, if that helps.

[@erichwise7734]

Would filling the voids with something like a wax work to keep other crap out?

[@DrShock]

That may also trap moisture, best maintenance after hitting this would be to just use a blow nozzle and puff it out during every tire rotation imo.

[@loganator78r]

Couldn't you use the rh plate for both sides?

[@DrShock]

As I showed in the video, both sides have different GM part numbers for a reason. They have slightly different physical dimensions making them side / orientation specific. Would it matter to use the wrong side plate if the axle housing was not suffering from corrosion, probably not. But given the corrosion on this particular trucks axle, using the correct side prevents further housing stress at the mount point that might lead to having to replace the axle prematurely.

[@loganator78r]

I was just thinking that if they match up one way and not the other. That if I were to just mount the rh side 180 degrees the other way onto the left hand side would work. I gotta do something since my u bolt broke and it's soo rusty.

[@thesalvagegarage]

I see I am about 20 hours late. I am trying to do this in my head, but if you turn a right side bracket 180 degrees, isn’t it now a left side bracket? That would explain why they discontinued only one.

[@DrShock]

Maybe. But they only discontinued what is typically only used on the 2500 size axles, not the 1500 version. Usually GM will issue a parts note for any substitutions, but they didn't do that for this particular part. I certainly think you can sub the RH side one in a pinch, but elected to keep it all original.

[@danielb-c9100]

Can you do a video of all your vehicles

[@hawkdsl]

Always replace the nuts and washers too. It's good practice to never reuse hardware on suspension parts. It's cheap insurance. No, seriously... It's cheap. Don't be that guy. And as far as the rear plates... Again.. Cheap. Your life is worth more then $25 bucks. If your doing this job, thank the old parts for a job well done, and replace everything with new parts.

[@DrShock]

Certainly something you can _optionally_ do for peace of mind. Inspect your parts and fasteners, discard and replace with genuine OEM parts only if necessary due to corrosion or physical damage. Otherwise, repair, restore and reuse in accordance with the GM service manual specifications.

[@pabunny]

I go to a breaker bar, if I see the impact driver struggling, much faster.

[@danieljohnson4418]

Great video. Poor design by GM. I wish I would have installed a u-bolt flip kit when installing my new leaf springs.