1989 Sierra Rear Suspension Question

[ssport94]

My 1989 GMC K1500 needs a couple of rear suspension parts to pass state inspection. These aren’t typical wear parts… the truck was used to haul a boat by the previous owner (15 years ago) and it’s really rusty underneath. I’m surprised that the rear axle hasn’t fallen off yet. The parts that I need are the following:

 

Spring Anchor Plates – these are the plates that mount under the axle tubes where the U-bolt washers and nuts are. Mine are pretty much non-existent. After talking to the local dealer’s parts department, there are left and right versions of these and they can still be ordered. Interestingly enough, the LMC Truck catalog only shows the right side for a ½ ton pickup.

 

Spacers – these are mounted above the leaf springs. These are formed to locate the U-bolts at the proper spacing. There are 3 different part numbers listed for these, apparently stamped with a “V1, V2 and a V3”. I have no idea of what mine had on it, because they’ve basically dissolved. Does anybody know anything about what the “V” numbers mean? The only thing I can think of is for different width leaf springs on ½ ton, ¾ ton and 1 ton trucks. Any help here would be appreciated.

 

U-bolts - according to the dealer, these come in M14x2-240 and M16x2-295. The M14 and M16 have to be the thread size and I’m assuming that the last number is the length. I can measure the length from what’s left of the original U-bolts, but the thread size is going to be tough. What should the ½ ton K1500 have come with?

 

This might all be clear if somebody has access to the parts manual, or better yet, if somebody has a link to an online version, please send it to me.

 

Thanks,

 

Mark

[JRLZ71]

My 1989 GMC K1500 needs a couple of rear suspension parts to pass state inspection. These aren’t typical wear parts… the truck was used to haul a boat by the previous owner (15 years ago) and it’s really rusty underneath. I’m surprised that the rear axle hasn’t fallen off yet. The parts that I need are the following:

 

Spring Anchor Plates – these are the plates that mount under the axle tubes where the U-bolt washers and nuts are. Mine are pretty much non-existent. After talking to the local dealer’s parts department, there are left and right versions of these and they can still be ordered. Interestingly enough, the LMC Truck catalog only shows the right side for a ½ ton pickup.

 

Spacers – these are mounted above the leaf springs. These are formed to locate the U-bolts at the proper spacing. There are 3 different part numbers listed for these, apparently stamped with a “V1, V2 and a V3”. I have no idea of what mine had on it, because they’ve basically dissolved. Does anybody know anything about what the “V” numbers mean? The only thing I can think of is for different width leaf springs on ½ ton, ¾ ton and 1 ton trucks. Any help here would be appreciated.

 

U-bolts - according to the dealer, these come in M14x2-240 and M16x2-295. The M14 and M16 have to be the thread size and I’m assuming that the last number is the length. I can measure the length from what’s left of the original U-bolts, but the thread size is going to be tough. What should the ½ ton K1500 have come with?

 

This might all be clear if somebody has access to the parts manual, or better yet, if somebody has a link to an online version, please send it to me.

 

Thanks,

 

Mark

Why not go to a junk yard and find a rear axle and other components for your truck? It would save you a lot of headache down the road

[dlewis1111]

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[ssport94]

I did call around to a couple of local yards and nobody had one with 3.42 gears. I think the cheapest fix is to just replace the U-bolts, spring anchor plates and spacers. I can probably get a measurement off of the U-bolts, but I'm not sure which of the 3 spacers I need. The LMC truck catalog only lists one spacer for 1/2 ton, and just one style of U-bolt, but the girl at their call center knew nothing about them.

 

Does anybody have any suggestions on other vendors?

[Graya25]

I'd try Rockauto, they usually match parts like that based on year, 2wd or 4x4, engine size etc.

 

And seriously.... Por-15 that rear axle. I thought my '97 looked bad before I POR'ed it, but that poor thing needs it worse than mine.

[ssport94]

I was thinking about wire-brushing it and doing the POR-15 while I had it apart. I didn't realize it was that bad.