TCC valve fix question

[Sunliner]

As a couple of you know, I have a '97 Blazer with the fairly common problem where it shifts hard from 1st-2nd when hot. Can turn the ignition off for a few seconds & will be ok for a while. Almost always sets a code 1870. Drives beautifully around town.

Ok...I changed the ignition switch thinking that might be the culprit, but no dice, still have the problem.
I think the next thing is to go ahead & get the Sonnax TCC apply valve kit installed on the valve body, as that seems to be the most common fix for this problem from what I've read/heard.

So far, I've called 4 transmission places and all will do this fairly reasonably. One shop though, insisted that I need to replace the torque converter as well, which will push the total bill up to about $550.00

Now...from my limited understanding, this *could* be a good idea since the 1870 is a component slipping code, but everybody else I've talked to said that theirs was resolved just by doing the TCC apply valve fix (and in one case, I think they also did a PWM sensor, but that's pretty inexpensive.)

My transmission fluid is nice and pink, doesn't smell burnt and my last excursion into the tranny pan ( a few weeks ago) revealed no large pieces of shrapnel or anything that looked like clutch material etc.

With that in mind, I'm wondering if I should replace the torque converter too, or just the TCC kit?
-Mike

[Allbert]

My advice is to try just the kit first. The only reason I can think of that you would want to replace the torque converter is if you strongly suspected that the converter clutch itself was bad. Also, I think the two jobs don't have a lot in common... you only have to drop the pan and valve body to do the valve repair, but you separate the tranny from the engine to replace the torque converter. Please come back and let us know if your kit fixes your issue or not. I'm wondering if you might also have a boost valve leak issue or maybe (less likely) a PCS problem.

[hazzzmattt]

before you do anything, check the tv cable adjustment and linkage then proceed.

[wolfox]

There is no TV cable in Blazers of this vintage. They are completely under computer control.

A quick glance in this fellow's profile:

" automotive technition "

Indeed.

[97BlazerDude]

Originally Posted by Sunliner

As a couple of you know, I have a '97 Blazer with the fairly common problem where it shifts hard from 1st-2nd when hot. Can turn the ignition off for a few seconds & will be ok for a while. Almost always sets a code 1870. Drives beautifully around town.

With that in mind, I'm wondering if I should replace the torque converter too, or just the TCC kit?
-Mike

I had the same problem on the same truck and decided to go with the replacement valve body like the TSB suggested (I am not saying the TCC kit is a bad idea - it must work or nobody would buy it).

My point is that I did not have to do anything to the torque converter and my problem went away. Shifts like butter and no more P1870 code.

[Sunliner]

I agree about the valve body; I just don't have the bucks for that at the moment. Hopefully the TCC fix will do 'er.

We're gonna find out in the mornin'. I'll keep ya posted...if nothing else, so someone else can learn from the experience.

Thanks for all the input, guys!

-Mike

[blazes9395]

If that is the problem with the valve body, the sonnax part will fix it, in fact it will be better than new, as sonnax did some tweaking to this valve. Its usually safer to get the valve body replaced, because you could have another problem on the valve body. this is what currently I am facing. I used the Sonnax part, and it fixed the TCC lock-up, its working flawlessly...but my 1-2 shift is still not up to my expectations, so now tomorrow I am in the process of opening up the tranny again and replacing the 1-2 accumlator. I did it myself(I purchased the reamer tool needed). You mentioned your getting p1870, so your most likely to get it right with only the regulator. Good luck!

[MRogers]

In my '89 I always have a hard 1-2 shift. Since this tranny isn't computer controlled, would the TCC kit on my Blazer, or is this a totally different problem?

[blazes9395]

Originally Posted by MRogers

In my '89 I always have a hard 1-2 shift. Since this tranny isn't computer controlled, would the TCC kit on my Blazer, or is this a totally different problem?

No, the valve body set-up is different. Did you check your TV cable though? It could be out of adjustment, which is causing high line pressure, giving you a harsh shift. Also, oil flush, filter and flush, is always a good idea every time the older transmissions start getting a loose shift.