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Chevrolet Blazer GMC Jimmy Transmission Problems

382 messages,  Last post on Apr 12, 2013 at 10:12 AM

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What is this discussion about? Chevrolet Blazer, Transmission, SUV

Messages Page 1 of 39

#1 of 382 where do i start ,transmission leaks 1986 chev blazer by larenz71

Aug 06, 2006 (8:12 pm)

I just bought my blazer and transmission is leaking. After purchase of blazer guy tells me it was a non op. What should I check for first , how should I approach.

#2 of 382 Re: where do i start ,transmission leaks 1986 chev blazer [larenz71] by repairdog

Aug 07, 2006 (3:12 am)

Replying to: larenz71 (Aug 06, 2006 8:12 pm)
86 Blazer don't know what you mean exactly - it works or doesn't? Sounds like it just leaks - if so look at the level on the dip stick, check the vent on top for the tube and cap, vac modulator on the side has a diaphram and vac line up to the engine, pan seal, rear seal, and front seal (that one will see fluid dripping out the bellhousing up front - requires trans be pulled to fix).

#3 of 382 Still Vibrating by blaze4x4

Aug 07, 2006 (4:52 am)

(2001 Blazer 102,200 miles) Well, I replaced the rear driveshaft U-joints (at the rear axle, two of the cups had rust inside), but I still have a harmonic vibration that seems to cycle. For whatever reason, this morning on my way to work, it started out REAL bad. As thing warmed up , it subsided, but was still there. Any history of a torque convertor going to pot on these Blazers. As bad as it was this morning, I gotta a feeling I'll soon know whats causing this, something is going to let go!

#4 of 382 Re: Still Vibrating [blaze4x4] by repairdog

Aug 08, 2006 (2:38 pm)

Replying to: blaze4x4 (Aug 07, 2006 4:52 am)
Could be the rear pinion bearing, transmission, or actual driveshaft out of balance. I always get mine spin balanced when replacing both U joints - they tack weld a small weigh on it. Looks like a 4wd and that output is thru the transfer case so they do have problems. If an LT with Autotrac the fluid is special blue synthetic called Autotrak II at dealer and its to quiet cluch pack chatter in the transfer case. Did this problem start and then you changed the u joints as a first shot? Is vibration speed related and seat of the pants or steering wheel shack? Could be tires if worst when cold. Had out of round rear disc/drum and they caused a hopping shack over 60mph.

#5 of 382 Re: where do i start ,transmission leaks 1986 chev blazer [repairdog] by larenz71

Aug 08, 2006 (4:33 pm)

Replying to: repairdog (Aug 07, 2006 3:12 am)
thanks for the advice i do appreciate it.

#6 of 382 Re: Still Vibrating [repairdog] by blaze4x4

Aug 09, 2006 (2:57 am)

Replying to: repairdog (Aug 08, 2006 2:38 pm)
I don't use the E brake at all. Last brake job, put new rotors on all four corners... seems like an out of round drum section of the rear rotor would have shown up then. The vibration was there prior to replacing joints. It is an Autotrac (4 button selector... 2Hi, 4Hi, 4Lo, Auto4wd). You don't suppose that as bad as the rear U joint was that it took out the pinion bearing (currently 102,300 mi.)? The vibration is always there, just some times worse than others. Most noticeable at speeds of 55 plus mph. Was on the expressway last weekend, and like to rattle my teeth out.I had the trans flushed, filter replaced at dealer ~22,000 miles ago. Vibration in the seat of the pants. I didn't replace front shaft u joints. I was told that until vehicle is in four wheel drive, shaft doesn't spin, is that true?

#7 of 382 Re: Still Vibrating [blaze4x4] by repairdog

Aug 09, 2006 (3:41 am)

Replying to: blaze4x4 (Aug 09, 2006 2:57 am)
I have one of these exact Blazers and they are known (sorry) for some vibration problems. Often nearly impossible to find/fix:
1. If not done already, change that front u-joint also and balance the driveshaft.
2. Have your tires force balanced that is computer read and it shows out of spec tires and heavy spots - 1 in 10 tires are often so far off they should not be used and sees bent rims/heavy spots in them too.
3. Check the trans mount and engine mounts for separation.
4. Put the Blazer rear end on jack stands and drums/disc on with at least 2 lug nuts, with a helper start and put in drive and you watch the rotating drum/disc and see it perfectly round and no oval - mine were - new ones are usually cheap China junk and I've had several bad ones recently as I've done 4 complete brake jobs in the last year on mine.
5. Check the rear calipers slides - bet you did not grease the pins in the brackets and they hang up and eat the inside of the rotor and drag. Also hope you put rebuild calipers on those rears cause they are a cheap single pison one that cocks in the bore and hangs often too.
6. Flush the transfer case and add the blue GM Autotak II syn fluid, and then drive 100 miles, reflush and add 2 new quarts - GM bulletin on this.
7. Have you replaced the lower ball joints - #1 weak spot, and looked at all steering jonts and greased all of them.
  
Thats a quick shot at some of the things to look at.

#8 of 382 Re: Still Vibrating [repairdog] by blaze4x4

Aug 09, 2006 (6:45 am)

Replying to: repairdog (Aug 09, 2006 3:41 am)
Looks like I have my work cutout for me. Although I didn't replace the rear calipers, I did remove the slides, wire wheeled the clean (yes, they'd been hanging up!) and greased (heavily). Earlier this spring, had upper and lower ball joints replaced, along with the idler arm and front end alignment, just before having the intake gaskets and thermostat replaced. Tires AND wheels are new (will have rebalanced). Thanks for all the suggestions. I'll pick away at them one at a time and let you know what I find.

#9 of 382 knocking sound by larenz71

Aug 09, 2006 (9:42 am)

I changed transmission fluid added a stops leak oil as well.I do have a knock that almost sounds like a diesel motor.It is not the motor, motor is strong. I was thinking possibly transfer case,drive line or axle.Am I close?

#10 of 382 Re: knocking sound [larenz71] by repairdog

Aug 09, 2006 (1:21 pm)

Replying to: larenz71 (Aug 09, 2006 9:42 am)
86 Blazer so 2.8L V6 motor? Is the sound always there even when not moving (in park)- if so rules out drivetrain.
Any smog pump on it? Vac hoses rotted out or leaks? Exhaust leaks, flange gasket, muffler. Need more info on the when/where/etc for noise. Crawl around and listen and post some specific clues for me.

Messages Page 1 of 39

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