The GMT400 thread (88-98 GM full-size trucks)

In reply to Cousin_Eddie (Forum Supporter) :

Wow, that looks so much nicer than what's left in Ohio.

eastsideTim said:

In reply to Cousin_Eddie (Forum Supporter) :

Wow, that looks so much nicer than what's left in Ohio.

 It's nicer than most of what's left here in Texas to be honest. 

I did some suspension work today. Fresh lower ball joints. Belltech 2 inch drop coils. Drop shackles in the rear. Belltech shocks all around. Freshly painted wheels with new 255/60 and 275/60 tires. Also got a nice Weather Guard toolbox for cheap off of Facebook marketplace. Tinted windows too.

In reply to Cousin_Eddie (Forum Supporter) :

Looks great!  ( I can't see the before photos in your post on page 7 for whatever reason).  

You've mentioned you have a lot of experience lowering these.  I had been figuring drop spindles in the front would be the hot setup but you went with springs.  Does that work out well and still let you use it like a truck?  I might like to lower my '89 some day but still be able to do full size truck stuff with it (namely haul cars on a trailer).  

I appreciate you sharing your experience.

In reply to Cousin_Eddie (Forum Supporter) :

It's awesome!  I'd love to have a clean GMT400 shortbed to play with.  I will probably have enough room for it at our next house too.

bought a cheap used cap. Any idea how to identify it?

I finished my suspension to a point where I'm pleased with it. In the end I'm running 2 inch DJM front drop coil springs, Beltech 4 inch rear drop leaf springs and Belltech shocks on al corners with shock extenders in the rear. It rides good and sits how I want it. 

Next up is a set of early model 8 inch wide rally wheels.

I love the work truck front end. I kinda want mine to have it, partially because then I could put some decent 5x7s in there.

In reply to Cousin_Eddie (Forum Supporter) :

This is the drop I've been considering as the drop spindles requires the newer style wheel bearing and such I believe.

How is it doing truck stuff? I use mine for box store runs for home improvement stuff and fire wood. 

In reply to Cousin_Eddie (Forum Supporter) :

That is sweet.  I believe you have hit the formula for lowering one of these without too much effort.  I really don't want to cut the leaf spring hangers off my truck for a 4-inch rear drop. And with drop spindles i'll have to ditch my 15" wheels. 

Be careful with drop spindles. I had DJMs and they changed the scrub radius enough that, combined with wide tires, it ended up tramlining badly no matter what you did with the alignment. I think they would be fine with narrower tires/wheels (I have 275s on the front). Stock spindles with the Ridetech front end fixed it and stayed at the same ride height, but it's a lot more $$.

I went with belltech 2" spindles and 4" hangers/shackles on mine. Nice ride and handles good.

mjrj (Forum Supporter) said:

In reply to Dusterbd13-michael :

Here's a side pic.  The fronts run on the tops of the fenders under compression (driveways etc).  Been told they will be rolled.  Don't know wheel dimensions.

A sister truck (color and step side) with Centerlines is for sale not too far from me.  It's super tempting.  There is also a cheap blown engine one near me too.  It'd make a good rust free blank canvass.

Question, any of you guys replace seats belts? My driver side seat belt(1990 1500 WT) seat belt receiver broke. It randomly unbuckles or some times doesn't unbuckle. I figured the belt is 30 plus years old and was looking to replace it. Found a few vendors but reviews are hit and miss and prices are from $100 to $300 and some of the bigger vendors don't show belts for the GMT400 Era of trucks, just the 87 and earlier.

GMC stepside V8 manual with bad faded paint and interior but no rust (TX) has me tempted right now.  Any tips on how to hide one of these from the wife?  

Now the ad shows a nice price drop and I have Friday off and it's only 3 hrs away......

In reply to AnthonyGS (Forum Supporter) :

Post pictures once you get it home

My new rotbox GMT400 W/T was delivered a couple of nights ago. Its my 3rd GMT400 but my 9th GM truck-y vehicle, and will mostly be used for property cleanup and hauling dirty things. 4.3/5spd 2WD. 1 owner with 176k on it. It drives very well but looks and sounds bad. I took this on the way back from lunch yesterday:

I'm not sure if I'll do much with it aside from the bare minimum rust repairs, tires, lights, and a massive cleanup.

So I just had to move my '98 K1500 to let my gf out and shovel the driveway and got a bunch of slip in reverse. Today's high is -20 deg C (-4 F), and it moved okay until I tried to turn. Truck is in 4wd, so I thought it was just binding a bit from the turn at first. Slips and grabs...truck sort of jumps and hops. Normally I always have the block heater plugged in and remote start it and let it idle for about 5 mins before driving, never have an issue. In summer I don't let it warm up and it's never had an issue, so it's a combination of the cold and trying to drive immediately after starting.

I've experienced this issue before, but it was right after changing the fluid and it was a little low - maybe about a year ago? Added a bit and hasn't done it since.

Here's the fluid level after idling for maybe 20 minutes. Engine not yet up to thermostat opening temp and just in park, so trans is cold but not -20 cold I'd assume.

What do you guys think, just low on fluid or a real issue? I want to check the trans fluid level again at operating temp and maybe add a bit, I don't usually drive enough to get the trans fully hot as my commute is about 5 miles.

If it's a real issue and not fluid level related, should I be thinking about a rebuild soon or limp it along until it gets worse? Truck has 192k kms (119k mi).The other part of me would love to 4L80 swap it, but I don't really need another project....

Every time I look at this thread I end up on CL and FBM looking for trucks.

Powar said:

I'm not sure if I'll do much with it aside from the bare minimum rust repairs, tires, lights, and a massive cleanup.

I've been picking away at the things that'll make this thing fail our (fairly simple and inconsistently enforced) out of state transfer inspection. The parts prices are awesome after messing with other things for the past few years. This repair cost me $32 total:

These little plug and play LED license plate light replacement assemblies were $13 on Amazon:

They're bright, not broken, and make the rest of the truck look even worse. Perfect.

Here's mine hauling ~1500lbs of steel tube for work a few weeks ago. It's not lowered, just squatting pretty significantly.

I've also managed to catch up on some maintenance and fix a few nagging issues in the past week or two:

-Front wheel bearings, which took care of the front end shimmy under braking that was starting to develop

-Did the XJ steering shaft slop (eliminates the rag joint) which took out about half the slop in the steering, although even after an adjustment the box still has a fair bit of play. 

-Snagged a color matching, rust free fender for the passenger side at the junkyard. I have a blue one for the driver's side too, although I decided to hold out for a matching one rather than taking the time to do that side as well.

-Last but not least, FINALLY solved the idle in drive/reverse issue it's had ever since the 5.3 swap was completed. Anytime it would be in gear at a standstill for more than a second or two it would start breaking up and running like absolute E36 M3, so I'd have to shift into neutral at red lights and stop signs. Yeah, less than ideal. Anyway, long story short, did some data logging and saw it was pulling a stupid amount of timing coincident with the issue occurring, and after another couple days of research and experimentation it all boiled down to literally changing a 1 to a 0 in some table to disable "brake torque management." Two plus years I've been dealing with this and that's all it took!

I did it again. And then again. I grabbed the red C1500 three weeks ago and did a bunch of little improvements and fixed most of the annoying issues, but it is going to need a full exhaust and windshield after the remaining rust repairs, so I decided to see what else was on the local market before I started ordering more parts. In comes this glorious bastard:

Its a '98 C3500 6.5TD/4L80E/G80 crew cab longbed, and it is cartoonishly long. I drove it home from 2 hours away and it never skipped a beat. There are at least 6 dents on every body panel, but it runs, drives, and stops just fine and I've not found any rust under it at all. The rockers and cab corners still exist too.

A friend of mine has a '93 C2500 extended cab longbed 5.7/4spd that he bought five years ago for $500. It needed a clutch (and one of everything else) to be back on the road. I offered him some heated shop space to do the work this weekend, so I towed it home with the new acquisition. I think we had 45 ft of truck in this photo:

Once again, the cheap diesel did great. After getting his truck into the shop and looking it over, he decided it was officially a parts truck and offered it to me and a friend to split for $200, so now I have 3.5 GMT400s, all purchased within the last month. I didn't really even intend to buy the first one. Now I need to swap some parts from the orange one to the other two when the weather improves a bit.

This is how it starts.  And then soon you're "that guy" with all those vehicles in the back yard, and then more and more and more of them start showing up, because people know you collect them.

Excellent progress!

I am envious.

In reply to Powar :

Welcome. You have been assimilated. 

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