GM newbie - been shopping for a 4X4 crew cab truck, all brands, looking for a '99+ diesel/manual trans, for daily driving and occasional towing of 7K load. found a GMC 3500 Crew at a local wholesaler with a 5.7L gas/auto, nice truck, I love it...but I don't know a lot about GM trucks. I am used to front leafs/coils, and don't understand the front IFS setup as well as I should to judge whether it is good - anything I should look out for? I would appreciate any info on what to look for (the left CV is noisy), and what the auto trans reliability is in this year truck. I have never owned an auto, so I have nothing to compare it to. Sorry to post as a newbie, but this truck is the nicest I've seen, maybe underpowered with the 5.7? Expected gas mileage with the 5.7L?

Dave
'79 Bronco
'89 Trooper

I don't think the 5.7 is too weak, I pulled a big a$$ rock saw, among other things behind my 1/2 ton without any power problems. The tranny is a 4L80E, it's a good auto tranny, and should not give you any trouble. As far as checking the IFS, I would look at the tires and make sure they are wearing evenly, may just be an alignment issue if they are not, but may mean more. Since the truck is I assume stock, I doubt there is any major problems under there though, but if there are, even an untrained I will pick off the obvious. I get great gas mileage with my 5.7 and 33's, so you should get about the same with the 5.7 and 4L80E. Anyway, you could always take it to a mechanic friend to check out before you buy it.

thanks, TX. appreciate the info on the tranny.
It has a 3" body lift (ugh!), with 33/12.50 BFG A/T's (not KO's), about 1" offset, no adverse wear patterns on the tires. tranny shifts strong, but I am concerned that with the larger than stock tires, and smaller motor, that I should regear. which brings the next question - what front and rear diffs were stock on the 3500?

Dave
'79 Bronco
'89 Trooper

Well, in 97 if you bought a K3500 crewcab, w/ a 5.7 and auto tranny, the only 2 options were 4:10's and 4:56's. My guess is that it probably has not changed, so you most likely have one of those.
These are 1997 stats:
a K3500 ccab 5.7 w/ auto (ball hitch trailring) max trailer weight w/ 4:10's is 6500lbs. w/ a tongue load of 800 lbs.

W/ 4:56's, it's 8000lbs. w/ tongue load of 950lbs.

A fifth-wheel trailer weight is the same as above, w/ a kingpin load at 3000lbs for both gears.

Hope this helps some.

Why would you say that the 5.7 is a small motor. It is a 350 with the vortec setup. Thats actually a pretty good engine. I dont think that you need to worry about the engine.


1973 K20 - 350/350/205 Dana44/14bFF

I would have doubts about a 350 in a truck that big. Reason I say so is because I have a 97 Crew-Cab Dually with a 6.5L. Unloaded this truck weighs in at 7800Lbs. The 6.5 has more than enough power and is better set up for hauling than the 350 would be. If you are serious about a gas motor go with 454 Vortec instead. You will probably get better MPG with the 454 than with the 350 (sounds hard to believe) but its true. Right now I am getting 16-17 mpg(winter diesel) and when I first got the truck in October I was averaging 18-20 with summer fuel my truck also has 4:10 gears and a 4L80E trany and is a 4x4. With a 454 you would probably get 12-14mpg and with a 350 close to the same. That is just highway or cruising. Haul 6000Lbs and the diesel will put out around 15Mpg, the 454 will give you 8-10 and the 350 will probably be down to at least 8 just because of the weight of the truck and the low gearing it takes to move that much weight.

Good luck with what ever you get...I my self will never own anything but a C-cab again...there great!!!!

Here is a pic of my truck loaded with 7000Lbs of gravel in the back (almost as much as the whole truck weighed!!! and honestly I could hardly feel the weight and power with the 6.5 was amazing, you could hardly tell it was weighted that much.


Ryan
1997 GMC 1-Ton Crew-Cab Dualie 4x4 with a 6.5TD
Chevy SuperStock 4x4 Truck Puller
Great Lakes Truck & Tractor Pulling Association
http://www.greatlakespull.com

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Front diff is a GM Corporate 9.25" IFS. Not the best for travel or flex, but beefy enough for tires up to around 38" or so and works great for towing.

Rear is a GM Corporate 14 bolt Full Floater. King of beef and Detroits are $330 compared to $500 plus for everything else.[img]/wwwthreads_images/icons/cool.gif[/img]


Chrome sucks
285/75R16, 255/85R16, & 305/70R16 fit on a stock GM IFS fullsize 4x4 truck when on the stock 16x7 rims.

Hey, no offense 73K20 - I have had 350's in my younger days, '70 Chevelle and '73 Nova, so I appreciate their worth, but on a 2+ton vehicle, I have concerns about being underpowered - for that reason was looking for a diesel or big block. Again, it drove fine for my purposes.
AJM - Thanks for the diff info, the rear looked like the 14bolt, but I had no idea about the front.
Would a VIN help nail down the engine size and other goodies for sure (anybody have a GM decoder)? - here goes
1gth33roxfo17204
Thanks for the info so far, and I appreciate any more info I can learn from the VIN.



Dave
'79 Bronco
'89 Trooper

I drove around a 1998 GMC 2wd Crew Cab long bed and a 2000 Chevy 2wd Crew Cab long bed for most of the last 2 years while I was in the Marines, and both had the vortec 350 and 4L80E. Both had plenty of get up and go. 4x4 would take some from it, but for daily driving it'd be fine. Start towing 7000lbs and you'd miss that 454 or 6.5L real quick though.[img]/wwwthreads_images/icons/tongue.gif[/img]


Chrome sucks
285/75R16, 255/85R16, & 305/70R16 fit on a stock GM IFS fullsize 4x4 truck when on the stock 16x7 rims.