I've been looking at transgo shift kits/reprogramming kits and I am wondering which is best to prolong the life of the 4r100 transmission. I understand that the chips will raise the line pressure and I wonder what effect that has on the pump. The valvle body raises line pressure to? Does that have an effect on the pump? I have heard good things from people about the reprogramming kit.

I thought these were electronically controlled transmissions? The reprogramming kit is mechanical. Anyone care to elaborate? Ken?

My main concern is better shifting and longer transmission life/cooler temps. How does the chip stack up to the reprogram kit and valve?

 

The line pressure increase is going to result in less clutch pack slippage and lower transmission temps as a result. Its not upped so high that the pump can't handle it. Keep in mind that while you may increase clutch pack life, band life can decrease it you firm it up too must with an agreesive kit (go with a firm, not hard kit).

Besides the chip, there are to basic types of shift kits: a) electronic kits that change the signal going to the transmission, increasing the line pressure in a manner similar to a chip (Banks has kits like this) b) kits that include valves that flow more than stock.

With the valve, because the stock computer doesn't know its flowing more and doesn't adjust the line pressure down, you end up with a pressure increase and get a firmer shift. If a chip were programmed to increase line pressure and you had a shift kit the shift would be way too hard for most people (which is why I don't program a chip to increase line pressure if a shift kit is installed).

If you're not looking for a very hard shift and just want to firm it up a little either a chip or a kit will be sufficient. If you want a very hard shift, a kit designed for this is best.

 

Thanks Ken

I've been doing some research on the net about the 4r100 tranny. What Gregg Evans and other say about correcting the deficiencies and weaknesses in the auto trannies makes sense to me. Just raising the line pressure masks some of the problems but does not correct them all. Shift kits raise the line pressure without any more pressure on the pump, that makes a lot of sense to me. My whole goal is to extend the tranny life and have a firm shifting trans and the shift kit is going to get me there for around $55.

People that buy a tuner or chip for the 87 program are just throwing money away IMO. The cost is just too high for what they are getting.(a line pressure increase alone) I'm up here driving around at 4500-9000 feet pulling a trailer and from what I read in one of your recent posts, you stated that for every 1000 feet in elevation a chip loses a chunk of HP (10% I think you said). So in my case I don't think it is advantageous to buy a chip because I would be putting premium in the X and losing the hp gains from elevation. What I really need is a good shift kit to fix the transmission weaknesses and go on my way. My V10 with an air induction and free flow muffler will give me all I need to motor.

I must admit though that the promise of increased HP's is still tugging at me. I am not by any means trying to bad mouth the chips. I think they have their place and IMO that is tweaking the engine. We need to get our trannies rock solid mechanically so they can stand up to the increases in performance from the chips and other add-ons.