Trans rebuild

**Logan541** · 12-03-2014

Ok torque converter not working properly, and it will not go into over drive. Local guy here who is known to be a good transmission guy says a complete rebuild of my trans will include all hard parts, replace only the bad solenoids, replace one solenoid with one that will increase the line pressure to 220 and install a Neil's shift kit. He says since my trans has 341,000 miles on it, he would rather do a rebuild rather than just change solenoids and add a shift kit. Just solenoids and kit $400-$500, the whole rebuild $1,200-$1,500 rebuild is one year unlimited mileage warranty, the other no warranty. I am leaning to the rebuild what do you think? and is the price good?

**1998gt** · 12-03-2014

what year is the car? that will give some insight

**Logan541** · 12-03-2014

1997 grand prix gt n\a

**GTPpower** · 12-04-2014

Yeah with those miles, I would do a full rebuild.

**Sven the Sexman** · 12-04-2014

There is no solenoid that controls line pressure on a 97 3800 NA. That trans has a vacuum modulator that controls line pressure directly and if it goes bad it can cause lots of fun things to go wrong. 1-2 and 2-3 have solenoids...then there's the TCC solenoid and the TCC pulse width modulation solenoid.

**BillBoost37** · 12-04-2014

A quick google search

Here's info about 4T60's that Sonnax has listed for problems and what typically goes wrong. Third one caught my eye as it's talking about TC.
http://www.sonnax.com/resources?utf8...lter#resources

A fix kit they offer
http://www.sonnax.com/parts/3033

Tons of info on it.
http://www.sonnax.com/units/264-4T60-E

Transgo
If we look at their shift kit jr, it includes valves for the valve body etc.
http://www.transgo.com/products.php?...product_id=220

In their product catalog it looks like they have the kit plus an accumulator kit
http://www.transgo.com/products.php?...&parent_id=105

Personally, I'd suggest reading up on all the info you can find for the trans (tons on Sonnax) and discuss those things with your builder. Make sure he goes right on through and does it all.

**Logan541** · 12-04-2014

So am I to assume that when the builder told me 340,000 on that trans and just now showing a problem is unheard of he was right? LOL, he wanted to know how I managed that and I told him drive fast but sane and do a fluid flush and filter change every 100,000 miles for the first 200,000 miles then after that just a fluid and filter change every year and a half

**BillBoost37** · 12-04-2014

I would also look into any upgrades that Sonnax/Transgo has available for your 4T60. In the 4T65 there are a lot of upgrades to the valves that require special tools to ream etc and they make a huge difference. By 150K most 4T65's are sloppy, the 4T60 valve body doesn't appear to be super different from a quick exterior view, but maybe it is.

**Sven the Sexman** · 12-04-2014

Originally Posted by BillBoost37

I would also look into any upgrades that Sonnax/Transgo has available for your 4T60. In the 4T65 there are a lot of upgrades to the valves that require special tools to ream etc and they make a huge difference. By 150K most 4T65's are sloppy, the 4T60 valve body doesn't appear to be super different from a quick exterior view, but maybe it is.

Valve body upgrades are possible for the 4T60 just like the 4T65. The major difference between the two is actually more minute...it's the way MLP is directed through the valve body itself. All the bores can still be reamed...the valve body can be upgraded in basically the same fashion as the 4T65 as long as parts are available. You can even utilize some of the 4T65 parts if you know what you're doing.