I am looking at buying a 1987 GMC Jimmy fullsize. The opometer shows 70,000 miles and it has a 6 sinch suspension lift it also has overdrive with a shift kit. i am going to be looking at it on Saturday. i was wondering if you could tell me a few things to look for and look at when i am checking it out. I have included a few pictures of what it looks like.

I will appreciate all the info that you can give.

Thanks

 

Looks pretty nice from the pictures. I'd check how they got to the 6" of lift. I'm not a fan of lift blocks over 4" tall in the back unless you are going to keep it on the street & not go too wild with the powerplant.

If the underside looks as clean as the exterior does from those pictures, the body should be in real good shape. I'd check out the steering box to frame bolts to make sure that the frame isn't cracked around them as is common when larger tires are put on these trucks (and can even happen with standard tires).

I believe that the cluster only shows to 99,999.9 in that year and if so, I would really question whether it was truly 7x,xxx miles or more like 17x,xxx miles.

 

Looks like a good truck Id check the fluids and take her for a nice test drive

 

Those were the first things that came to mind while reading your post. I've got an 89 and you'd have to put a 2 in front of that 70,000 to be accurate. And as mentioned, take a really good look with a flashlight at the frame where the steering box attaches for cracks. Can't stress that enough. I looked at many blazers for my friend and every one had hairline cracks there, and the owners were dumbfounded when I mentioned it to them, one even asked if that was bad.

So a 6 inch lift, that opens a whole can of worms:

Lift blocks create axle wrap. And under no circumstance should lift blocks be on the front.

Have the brake hoses at the front wheels been replaced and do they have enough slack. Was the brake hose above the rear diff replaced.

Was the rear driveshaft replaced or lengthened or had a slip yoke eliminator kit added, if not it's probably going to detach from the transmission if you get any droop in the rear when you off-road. You may get some driveline vibrations because of the steep pinion angle or it'll eat through u-joints.

What about the front driveshaft, is it even still attached. Some ppl have been known to remove it when they start lifting it that high because the u-joints will bind and break. That'll be a major weak link in the front end.

I think stock tires were either 29 or 31 inches, those look like 35s. Did they change the ring and pinion on both the front and rear accordingly. If not then it'll be very slugish. An easy way to check is when you're on the freeway and traveling with the flow of traffic does the speedo say you're going 55? And to check to see if they replaced both front and rear R&P get off-road momentarily (shoulder of the road is ok as long as it's loose gravel) and engage 4WD. The front and rear tires should rotate at the same speed. Also, listen for any odd noises while in 4WD.

Get underneath and look for any fluid leaks: engine/tranny/transfer/case/diffs

While in park have someone move the steering wheel back and forth just enough to put a little pressure on the steering components. Check for any play.

Did they replace the steering arm with a raised one, if not you'll have really bad bump steer.

With the engine running pop the engine oil fill cap off and look for excessive blow by.

Does the driver's side door have any play in it - if you lift it up does it feel loose? You will notice that you have to slam the door shut or lift up on it to close it. (worn hinge pin bushings)

Does it have electric windows? Do they operate slowly - check rear window too.

That is a pretty truck, almost too pretty. Check the engine compartment firewall to see if it's a different color or not matching. That's a sign that it may have had major body work and they just repainted the whole thing while they were at it.

I just noticed that the body emblems on the doors should be on the fenders (depending on what they say) or the fender emblems are missing - why? (see above)

Do a carfax!

Sorry I couldn't be of more help. But that should keep you busy for a few minutes checking things.

 

Thank for all the info. it will help when i go and check it out.

 

I was wondering what stock gear ratio came in the 1987 GMC Jimmy. It has a 350 TBI engine.

 

Could be 3.08 (GU4), 3.42 (GU6), 3.73 (GT4), or possibly 4.10 (GT5). Take a look at the service parts identification label on the inside of the glovebox door and you should find one of the four numbers I have included above. G80 means that it has the gov-loc, self locking rear differential (not really a good thing in the early forms).

 

Can anybody get a build sheet if I provide a VIN number or get the RPO codes that came on the vehicle.

 

It's might be too old to get that info from CompNine.com's VIN Decoder, but it's worth a try.

 

I tried that and it didn't work. Thanks for the info.