1999 Chevy Blazer slipping transmission

Status
Not open for further replies.
Joined
Apr 13, 2013
Messages
9,246
Location
FL, USA
My brother recently got a 1999 Chevy Blazer with the 4.3 V6 and 4 speed auto with 234K miles. Just yesterday when driving on the highway the transmission began slipping. He told me it was slipping from 2nd to 3rd, and from 3rd to 4th. He also mentioned that it didn't start right away, it wasn't until being on the highway for a while that it started slipping. Once he reached his destination it sat for a couple of hours then upon returning the same thing happened. No slipping at first then slipping after driving for a while. So maybe it has to do with the thinning of the fluid as it heats up? I don't know. Anyway, I checked the fluid last night at its brown and does not smell fresh. Its not black and doesn't smell like burned toast or anything but it definitely needs to be changed. He is taking it in tomorrow to have it looked at and possibly change the fluid and filter if the shop thinks that is in order.

I know 234K miles is a lot of miles but he has been in this car many times before taking ownership and it didn't exhibit these signs until now. Is there a good chance that a fluid and filter change will rectify the issue? Either way, I will updated tomorrow if he finds something out.
 
Originally Posted By: clinebarger
The 3-4 Clutches are smoked, They will hold 'til the unit is hot. Rebuild time!


Is this common for this unit? It just seems odd that it would happen practically overnight.
 
Originally Posted By: gregk24
Originally Posted By: clinebarger
The 3-4 Clutches are smoked, They will hold 'til the unit is hot. Rebuild time!


Is this common for this unit? It just seems odd that it would happen practically overnight.


VERY common issue! It can happen just driving down the road.
 
Originally Posted By: BrocLuno
Drain some and throw a couple of qts of Tran-X in it and limp around until you can get it rebuilt. It's a decent tranny, but this one needs work ...


Originally Posted By: 901Memphis
A couple quarts of type F transmission fluid will limp you until you can buy a new or used 4L60e


Neither one will help a burnt down 3-4 clutch.
 
While it's true that if things are done inside, they're done. But performing a pan drop/filter and refill might solve the issue.

Automatics are made to work with fresh fluid. If the fluid's been going too long it could exhibit the behavior it has. Nothing lost by trying fresh fluid except a few dollars. If it doesn't work it doesn't work.
 
Originally Posted By: Miller88
If he keeps driving it with it slipping, any chance of it had of ever working again will be lost


I have told him this already. He hasn't taken it on any long jaunts. Most everything is within 5 miles where we live.
 
Originally Posted By: Kuato


While it's true that if things are done inside, they're done. But performing a pan drop/filter and refill might solve the issue.

Automatics are made to work with fresh fluid. If the fluid's been going too long it could exhibit the behavior it has. Nothing lost by trying fresh fluid except a few dollars. If it doesn't work it doesn't work.


I've been a transmission tech for over 25 years, I have never seen anything short of new 3-4 clutches fix a 4L60E or a 700R4 that has a slipping 3rd & 4th gear.

High mileage 4L60E's can also strip out the splines of the 3-4 frictions.....The friction material itself will be fine, But no splines to drive the Input Carrier Hub. But generally it will just strip the 4 middle frictions & the 2 outside ones can't hold & they burn up. 4.3L trucks are the worst about this because the harmonics they produce vs a V8.
 
Originally Posted By: clinebarger
Originally Posted By: Kuato


While it's true that if things are done inside, they're done. But performing a pan drop/filter and refill might solve the issue.

Automatics are made to work with fresh fluid. If the fluid's been going too long it could exhibit the behavior it has. Nothing lost by trying fresh fluid except a few dollars. If it doesn't work it doesn't work.


I've been a transmission tech for over 25 years, I have never seen anything short of new 3-4 clutches fix a 4L60E or a 700R4 that has a slipping 3rd & 4th gear.

High mileage 4L60E's can also strip out the splines of the 3-4 frictions.....The friction material itself will be fine, But no splines to drive the Input Carrier Hub. But generally it will just strip the 4 middle frictions & the 2 outside ones can't hold & they burn up. 4.3L trucks are the worst about this because the harmonics they produce vs a V8.


I bow to your greater experience level.
 
Originally Posted By: clinebarger
....High mileage 4L60E's can also strip out the splines of the 3-4 frictions.....The friction material itself will be fine, But no splines to drive the Input Carrier Hub..........

+1
thumbsup2.gif

Ever wonder why a thicker higher viscosity gear oil is preferred ... to lighter lower viscosity oils...... ?
Synchromesh >> Dexron III >> LV Dexron VI ..... in an auto transmission, shiftability aside and;
GL5 85W140 >> SAE 90 >> 80W90 >> 75W90 >> xW80/5 ...... in a differential .

Edit:Another incidence of inadequate (technically speaking) but optimum (marketing speak) factory recommended viscosity grades ........
https://bobistheoilguy.com/forums/ubbthr...ise#Post4352188
 
Last edited:
Originally Posted By: zeng
Originally Posted By: clinebarger
....High mileage 4L60E's can also strip out the splines of the 3-4 frictions.....The friction material itself will be fine, But no splines to drive the Input Carrier Hub..........

+1
thumbsup2.gif

Ever wonder why a thicker higher viscosity gear oil is preferred ... to lighter lower viscosity oils...... ?
Synchromesh >> Dexron III >> LV Dexron VI ..... in an auto transmission, shiftability aside and;
GL5 85W140 >> SAE 90 >> 80W90 >> 75W90 >> xW80/5 ...... in a differential .

Edit:Another incidence of inadequate (technically speaking) but optimum (marketing speak) factory recommended viscosity grades ........
https://bobistheoilguy.com/forums/ubbthr...ise#Post4352188


I'd hardly blame the factory suggested fluids when they were arguably used well beyond their intended service interval. 200K+ on a domestic 4x4 auto transmission with most likely original fluid is pretty good IMO.

As far as the thicker gear oils, you really can't go any thinner to the weights you mentioned. xxw-90 is average here whereas xxw140 is the thicker HD stuff.
 
Last edited:
Originally Posted By: clinebarger
The 3-4 Clutches are smoked, They will hold 'til the unit is hot. Rebuild time!


+1 There isn't much you can do in terms of limping it. I would shop around for a reputable transmission shop and have it rebuilt. Those transmissions are solid and easier to work on. Cant imagine it would break the bank for a modest rebuild. Consider putting maxlife in it after the rebuild. Should help prolong it
 
I drove it tonight, it is slipping BAD from 2nd to 3rd and from 3rd to 4th. Any moderate amount of throttle and it will not shift, you have to feather it to have it go into 3rd and 4th. It is getting checked out tomorrow by a local shop.
 
Remans are around a grand (plus core) on eBay and Rockauto.
So there's a benchmark.

Rebuild parts kit + a new converter roughly 300 bucks.

Auto trans failure is the "cause of death" for a lot of old vehicles where it's not considered worthwhile to spend the money to get it back on the road.
 
Last edited:
He got news today that indeed the trans is shot. He will purchase Lucas to see if it will buy him some time.
 
Status
Not open for further replies.
Back
Top