89 GMC V2500 Burb WONT BURNOUT.

[1979C20]

Just wanted to see everyone elses experience when it came to their suburban and spinning tires. Ive got 4" lift and 35s, TBI 350, TH400, and I believe 4.10's. I cannot get this truck to spin a tire even when it raining. Its kind of irritating. Any suggestions?

[Captkaos]

Are you wanting them to spin for a reason?  Is it dying or just straining?  If the engine is stock that is a lot of tire to ask for it to spin.

[1979C20]

Not for any specific reason. Im pretty sure it is a crate motor for summit. It is surprisingly clean, the whole motor is black, it has chrome center bolt valve covers and chrome timing cover. My buddy has a 1990 burb, same truck, same setup and he can spin tires without even trying. Im just wondering if there is something missing or wrong with my truck.

[Captkaos]

Does everything check out ok?  Good compression, timing, vacuum, etc?  Do you know which motor it is?

[Irish_Alley]

how much meat is on your tires?

[1979C20]

Not sure which motor, it was in the truck when I got it from one of my friends and he didnt ask the PO anything about it. I will check those things this week and post my results. Thanks for the suggestions.

[dvdswan]

my thoughts are...
how many miles are on it: engine, trans, etc?  it all could be very tired.

just because an engine looks fresh doesn't mean anything, it could have been pulled to get resealed and reinstalled.

what is the condition of the oils, is there a sign of age?

are you sure of the gear ratio?  have you physically checked it or gone off someones word?

does the trans start in first?

when was the last time it had a tuneup? wires, plugs, filter: fuel and air, cap, rotor, etc.

tons of things can add up to one big cause.

[bd]

In addition to the preceding suggestions, check the timing chain stretch and verify that the balancer hasn't spun on its hub, giving you a false indication of ignition timing.  Make sure the distributor advance mechanism is working as it should.

[Greybeard]

One other thing I had happen to my 86 Blazer was the over-drive stuck on...but you said it has t400? I wasn't aware a t400 was available that late? Live and learn. I would have thought it would be a 700R4? Doesn't mean anything anyway, if the engine is aftermarket no reason the tranny can't be different also.
AS dvdswan asked does moving the gear shift to the first gear position do any good? Maybe your linkage isn't right and it's not hitting first.

My wild guess is the tranny is simply old, tired, loose and slipping... I can relate! Change the fluid and filter, install a slight shift improver kit and tighten it up some

I've never owned a auto in a truck...never seen the point myself but all of my cars had autos. They work good for rock crawling, I'll take a clutch for everything else. Way to easy to burn a auto out in mud or water. At least it used to be. YMMV. Besides, I wheeled for full week once with a blown out clutch bearing. Just started it in low range granny whether in 4 ' of water or where ever I happened to be, then drove 100 miles back to St. Louis with no clutch. Can't do that with an automatic.

Reminder, do not get in a hurry and forget to lube throwout bearing or the front bearing retainer housing it rides on in a new clutch install, then immediately drive on the highway for 2 hours, drive to the river and dunk the now really HOT throwout bearing in cold water. The front bearing retainer housing on the tranny shatters when this happens because the bearing will seize on it twisting it off. Turns out I forgot to adjust the pedal also and it caused just enough tension on the bearing to cause it to spin the entire time apparently. Do'OH! Live and learn....

[1979C20]

It is a th400, and It was rebuilt by a shop here in town 6mos ago. I just recently changed the trans filter and fluid and engine oild. As well as plugs, wires, and air cleaner. All engine sensors, distributor parts, and coil are about 1y old. I removed my NSS/REV switch from ky column went I rebuilt it, so my truck will start in any gear, also I know the linkage is adjusted properly because I 4 wheel a lot and it stays in first gear. My tires are 35's with about 70%. The odometer is 160k, documented. Whats the easiest/quickest way to tell if my motor may be factory or aftermarket? Casting number behind the head?

[dvdswan]

well, I would verify you gear ratio then.  you believe them to be 4.10s, verify them.  then you will know.

[1979C20]

I am certain it is the original axle and my rpo sheet says gt5 and g80 which is 4.10 with the gov lock.

[dvdswan]

ok, sounds good.  did things check out on the engine?  silly question, you're not trying to do this in 4HI are you?

[1979C20]

If that is a silly question, then would a silly answer be yes?

[Irish_Alley]

kind of brings up the saying there's no such thing as a stupid question, just a stupid answer.