1998 Chevy Blazer transmission question

Not sure if there are any common failures. Have a 1997 with 140K and 2000 with 289K. Both original transmissions, fluid & filter services about every 75K miles. Have done a fair amount of towing with the 2000, has tow package and never, ever pull anything while in OD. Have lots of tranny shops for customers and this is their comments on killers for the blazer automatics. Unless its a 2 door blazer I don't think you will find a swap out auto to manual transmission set up. If I'm wrong I'm sure some one will pipe in.

The week link is the 3-4 clutch pack and the sun gears. They usually don't get serviced and the fluid fries the trans clutches out. If it's burnt, it needs a rebuild. 1200 was cheap. Around here there 1800 plus the R+R. Comes to like 2100-2200. It's not rocket science to build one like the trans shops would lead you to believe. You do need a fair amount of know how, where to inspect key wear parts and a clutch pack press. Any trans shop can do the clutch drum packs for you. Most won't. The valve body is key with all electric operated valves it must be smooth, clean and right. They go for a grand + these days. If your TQ converter is good it can be drilled, cleaned/flushed, tapped/plugged and reused. Most shops replace damaged hard-parts, flush the converter, toss a seal/gasket kit in it with new clutches and steels. Not much else to it but a pump and some planetary sets.

" Unless its a 2 door blazer I don't think you will find a swap out auto to manual transmission set up."


They made 2x4 and 4x4 ones, just not many. Two door stick 4x4, never seen one.
They are out there. Rare and hard to find. Even harder to sell.

Originally Posted by sawmilleng

KAM,
I'm thinking about your suggestion of my rebuilding the transmission. I've never done a car transmission but have stripped and rebuilt a D4 Cat powershift transmission and torque.

Thanks!
Jon.

One thing if you do rebuild it make sure your bench is clean and I was told not to get any lint in the valve body or other parts.
I took the advice and cleaned everything in clean solvent and then dried with air pressure.

The rebuild kit I bought had all the gaskets, seals, bearings it also included the clutch disks and steel plates. I had to make a few tools to compress the clutch pack spring very simple to make.

Does the vehicle move? If so does it upshift, attempt to shift? what's the fluid smell like, is fluid level low? Check engine light on? Not doubting the bad transmission diagnosis but there are other things to consider before condemning the transmission itself. If it does move but no upshift could be a solenoid problem, valve body problem or even something not even attached to or related to the trans. If vehicle does not move and you decide to repair yourself I would not risk drilling and flushing the converter replace it with a remanufactured unit. It could be bad itself and you just transferred the problem. If you opt to fix yourself, have never done a car trans and do not have some special tools. It was mentioned earlier about making tools, certainly can be done as I have made many when I was building transmissions. But there are some that you just can't make and some are not inexpensive. Probably not the transmission you would want to have a first experience with. Just my .03 (.01 for inflation). This forum teaches we all start somewhere and learn from what we do od didn't do.

Originally Posted by sawmilleng

The transmission problems are straightforward--it started to not want to move. You had to rev it up a lot to get it moving. Once under way, it seems to shift ok. It didn't take long before it wouldn't move at all. That seems to point at the torque. But doesn't the torque oil circulate through the transmission as well? Or am I confusing the operation of a heavy equipment torque with an automotive torque? Also, even if it is the torque, you gotta drop the transmission on the ground to get at it...why not have a look at the tranny at the same time?

The oil smelled burnt before it started its problems; we dropped the pan, and changed the oil and filter pickup. I doubt it was changed since new, and has 175K km on it now. It started the problems after this and we are wondering if the pickup dropped off the intake--it is just a friction fit. Because the wife had a mail route and my pickup was also on blocks we were forced to continue just using it. We tried making sure it was full of oil so if the pickup was leaking it would still get oil. No change.

By the way, it's a 4 door 4x4. We bought it about 3 years ago, paid way too much for it, so I want to fix it up so we can use it to get some of our money out of it. My wife quite likes it...

I don't have any problem pulling it and stripping it. I'm a pretty methodical guy and will get the appropriate manuals beforehand. I understand GM has a pretty decent rebuild manual for the transmission...?

Thanks for all your responses--they help!

Jon.

Torque converter circulates oil similar to that on heavy equipment. If your problem agrivated after changing the filter make sure the filter you use is for the correct depth pan, there are two options. If fluid is burnt bad, will likely have internal issues that your disassembly will discover. ATSG (automatic transmission service guides) Are excellent manuals also. You can get them on-line at various places. I used these in the days I built transmissions, I got some of mine at my local NAPA store. Good Luck, hope all goes well for you.

Originally Posted by lousypirate

oh, if they are 4l60E's, you should look into putting one from a 1500 silverado or sierra into it. much more abundant to find a used one

I helped rebuild one, and did my own th350. They aren't bad if you have the right tools.

I would think that vintage would be a 4L60E as that is what is in my '94 Roadmaster as well as in the '03 GMC Sierra 1500.
One would hope that the spline counts would be the same on the output shafts on the 4.3's tranny as well as the V8's.
Wouldn't surprise me if the 1500's or the cars spline count was the same, ...might even be able to use a 2wd tranny and swap the rear casing of the tranny if the output shaft is the same length.
If not could still be used by reassembling with the original output shaft, ...but that again entails a fair amount of work as well.
D***, It'd be nice to have a Tranmission tech as a friend to verify what I am sorta semi guessing on here.

I think the spline count might be ok with 1/2 ton tranny but would be higher on 3/4 ton or more due to larger Dia. shafts. is what I'm getting at.

I'm not a mechanic by trade so if anyone that might have experience or know better, ...please correct me if I am wrong.