Tell me about your feelings on GMC Jimmy

[Fudgieghost]

Looks like I may be buying a 1998 GMC Jimmy w/ 55K miles on her. . .

Looking thru the 'net I see mixed reviews of this truck.  Some seem to be the result of people who seem not to realize that you actually need to do maintenence and sometime replace parts on vehicles. . .

And what's the story on Dex-Cool coolant?  It seems this truck is using that---coolant was orange.  I see there are lawsuits against GM about that stuff. . .

[...has left the building.]

I had a '96...it was my first car. I loved the truck other than the mechanical issues that it had. At 75K miles I had to replace most of the cooling system because of the Dex-Cool issues. At that time, I was not mechanically savvy so I didn't really know why they replaced it. In addition, the rear windshield wiper motor seized up as I was taking it to sell so I could purchase my first M-B. Been through GM, M-B, BMW, and Ford...now I only will buy Honda or Toyota for a daily driver.

[cfabe]

I like the s-trucks. Is it a 4x4 or 2wd? From my experience they tend to wear out ball joints, and front hubs(on 4x4). I'm not sure if 96 was past this, but some of the 'vortec' 4.3L models had issues with a leaky fuel pressure regultor that would eventually dilute the engine oil and cause premature engine failure. Luckily, most repairs are cheap and every corner garage can do the work.

[Fudgieghost]

Well, for the budget I'm on, and in the area I live, Hondas are only available with lots of  miles---many have over 100K and they're asking 8 or 9K for them.   Doesn't seem to be a good investment, even though I know they can last for another 100K. . . they last, but you do have to replace timing belts, radiators, wheel bearings, rotors, water pumps, etc.  Those things aren't cheap. .

Well, if and when I take possession of this Jimmy, first thing that happens is a complete acid flush and new coolant. . .  Also needs new suspension arm "stops" on the frame---but that's not really a big deal.  Other than that the truck is in excellent shape---no rust, clean oil, clear exhaust on cold start, etc. etc.

[Fudgieghost]

cfabe: Yes, that's one reason I decided to buy it----parts easily available and not too pricey, and, like you say, if you do break down out of town, local shops should be able to fix relatively easily.  

This will be a second car for us.  We have (4) drivers, and we've been living with one car.   You think that should be no big deal, and I guess if we HAD to, we could get by.   But come the weekend, my wife needs to go here, many times I'm working in the city, or elsewhere, and one of my sons is either working or needs to go somewhere . . .  gets to be a logistical pain in the . .

So, this truck won't be driven more than, say 8--9K miles a year. . .maybe less. .

[Parker Dean]

Transmissions tended to be a problem for GM trucks up through about 2003 or so.

Most common problem was with the torque converter clutch (TCC) system. Theres a check valve in the valve body that wouldn't seat completely and would allow the TTC apply pressure to bleed off and result in partial engagement of the converter clutch. This would result in either a severly overheated transmission on long trips, or a converter clutch worn through to the metal and causing massive metal contamination of a complicatd hydraulic mechanism, AKA an automatic trans. Lots replaced under warranty. Lots would make it to 60-80K miles.

Next most common invloled a little item referred to as a sun shell. It has a flange that connects to the input sun gear. This flange is welded on to the stamped steel sun shell and it breaks off right at the weld. GM later upgraded the sun shell so that the flange doesn't break off. Now the splines strip out! :bangs head against wall:

And another frequently-seen failure involves the roller bearings. The most common one to fail is in the forward planet, and when it comes apart the needle bearings get in the planetary gears which they destroy while getting ground into fine metal debris which ruins everything else. Note that this is just the most common one to fail, not the only one. There are at least to more positions that I've seen on multiple occasions.

Those are the most common failures of GM transmissions of that time. After that you have the usual oddball failures like planetary gear pins pushing out, snap rings breaking, seal and bushing failures that happen to any trans.

[Fudgieghost]

Parker: would a routine inspection/service of the tranny reveal these things, or would it take a complete or partial disassembly of the unit?  I also plan a tranny service if/when I take possession. . .

[Parker Dean]

Parker: would a routine inspection/service of the tranny reveal these things, or would it take a complete or partial disassembly of the unit?  I also plan a tranny service if/when I take possession. . .

Naw, not really. The sun shell and roller bearing failures are catastrophic failures (ie happen suddenly), so by the time it shows symptoms it's already too late.

The slipping converter could possibly be caught by someone looking specifically for it by watching things like how reliably the converter locks and how long it takes to do it. Looking to see if the converter is heat discolored. It should be steel grey, if it's brown it's been hot. And perhaps a pan inspection to look for clutch material and fine metal debris. Late model trans tend not to have any visible clutch debris, so if it's got a fine coating of dark powder coating on the bottom of the pan, somethings up. Also there is a magnet in the pan. A light coating of metal debris is ok, but if the layer makes it hard to see the shape of the magnet, again somethings up.

[Fudgieghost]

Parker: thanks for the info!

[gunsmith]

i have allways wanted one ...but only because of a greatfull dead song.
i know nothing about them.

[...has left the building.]

Oh I forgot that my fuel pump died at 60K too.