Turbo 350C to 4L60E

[Guardian]

Just as an update on the orginal post...
I have located a TH350 that is a buildable core and that should solve the first step. Secondly I decided to change the final drive but haven't decided on a ratio yet.

 

[HotRodPC]

I guess I never did ask in TX where you are. I have buildable Th350 cores. How much are paying for one? Not alot I hope.

If you don't tow much or light duty, you might consider keeping the 3.08's with the Non OD trans. But, 3.73's would sure be a middle of the road choice but with no OD and OEM size half ton radials, you'll be turning some rpm at highway speeds.

 

[Guardian]

I'm in the Dallas area. I have found several between 75 -100. Figured I could go through it and swap it at the same time I did the rear end. I have been considering going to 3.42 ratio for now, haven't really got a answer either way from all the research on the OD trannys. Hell that is why I am considering swapping out the top end of this motor, if it is going to be too expensive to drive daily then I might as well have a play toy.

 

[Guardian]

Just to update this thread. I pulled the 350C out and wanted to look inside , just for grins. I found the torque converter had apparently busted a bearing and seized on the end of the input shaft. This actually popped the input shaft out of the forward drum. I cleaned up the rest of it and have a new front drum and torque converter coming this weekend. I will try and get pictures up soon.

Hell I don't know how it was still driving. Guess I learned something new on this one, lol.

 

[HotRodPC]

Just to update this thread. I pulled the 350C out and wanted to look inside , just for grins. I found the torque converter had apparently busted a bearing and seized on the end of the input shaft. This actually popped the input shaft out of the forward drum. I cleaned up the rest of it and have a new front drum and torque converter coming this weekend. I will try and get pictures up soon.

Hell I don't know how it was still driving. Guess I learned something new on this one, lol.

You didn't get a new front shaft too? I think I woulda. I think I would have looked for a front drum and input shaft already pressed together. Even used is as good as new for that part.

 

[Guardian]

Yea they will come in put together. Guess I should have made that a little bit more clear, I have been up way too long today and am getting a little fuzzy.

 

[GOBR]

My 350c has a vibration also. Along with a ticking...... Have to shift manually from 1st to 3rd around 35 mph. 2nd will hold upon a downshift but slips like crazy. 3rd is also slippin like crazy. I have a knock like convertor bolts are loose but I have to overfill to get it to hold any gear. I know the pump is goin out.

I picked up a TH350 friday for $350 without converter and have an ACC 2200-2400 stall at the shop. Its goin in tomorrow.

Instead of the 4L60 unless its one of the early models, I would look at a 700R4 first. Get you some 3.73's and the 700 and youll be happy. Right now I have 3.73's or higher with a TH350C.............. SUCKS ASS!!!!! 50mph is 85mph!!

 

[Guardian]

I actually stayed with the 350C for the moment. I am looking at some other upgrades to the truck and didn't want the expense or downtime right now. Should be okay ofr the daily driving, just have to watch the launches, lol.

 

[GOBR]

My 350 C has been goin out for months. Drive like pa-paw and your good lol

 

[Guardian]

It has been holding up fairly well. Did a little reprogramming to firm up the shifts and it works good. I have not tried matting it yet, always too much traffic, lol.

 

[Guardian]

Here is the picture of the vibration source I had. The new tranny is woking out fine so far.

 

[HotRodPC]

Input shaft seized into the TC? Never seen that one before.

 

[Guardian]

Neither had I!! Don't understand how it was still driving but it was.

 

[HotRodPC]

The input shaft teeth were obviously still engaged in the direct drum. Obviously very loose and didn't break the drum out, but at least made the hole bigger because that shaft is a press fit in the drum. It got big enough to not be a press fit but not so big the splines still connected. I'd throw that drum away ASAP so it doesn't get mixed in with known good parts. I never let bad parts sits around. They go straight to the scrap bin so they don't get used accidently or I look up on the shelf and think I have something in stock.

 

[Guardian]

Yeah, it went in the junk bin. The front drum, input shaft and converter all got replaced. When rebuilding this thing I went ahead and put a transGo kit in it.