How to remove a shift kit?

[Bonnewagon]

I have a T-400 transmission that was rebuilt and has very few miles on it. The problem is that the prior owner put a shift kit in and can't remember what kind or what level. I would like to use it since it is fairly fresh but I don't want an unstreetable headache either. When he had it rebuilt he had the shop do the shift kit. The way I see it I have two choices. Put it in a car and drive it. If it is unruly out it comes. That is the hard way but probably the smart way. The other way is to open it and drop the valve body for a look-see. I did put a Transpak in a T-400 many years ago and I don't remember doing anything that was non-reversible. Please advise.

 

[Texas82GP]

Isn't it common practice to enlarge passages by drilling when installing a shift kit? Seems like that would be hard to undo.

 

[Longroof79]

I guess depending on what kit is in there, in some cases the separator plate is either replaced or drilled in a few strategic places and check balls are moved around or added.

Mark, if your friend could ask the trans guy who did the work, maybe he could tell you which kit is in there, or what brand he likes to use.

Perhaps your friend could tell you how the trans shifted, whether it was a mild firm shift, or harsh, very firm shift. What was the trans out of?

 

[monte olrac]

Put it in and drive it, i doubt he did anything serious beyond that shift kit, and even at level 3 so to speak it wont be anything harsh. if so he would know by the money he spent on everything else he did to make it that way

 

[-83MONTESS-]

I have never installed a shift kit that wasn't reversible. That being said I really don't see a shift kit being an issue on the street. Unless they went with some crazy kit I haven't heard of or a totally different valve body. I'd run it!

 

[Texas82GP]

The seperator plate is the only thing drilled? I agree with the others, put it in and drive it.

 

[lilbowtie]

If it has a modulator I would run it. The shifts should be normal unless your into the throttle.

 

[Bonnewagon]

Yeah, it's a total unknown. This guy is 46 going on 16, if you catch my drift. He doesn't remember anything. It was in a '79 Buick LeSabre that had a 1970 Stage 3 Buick 455, which he managed to blow up. I know he built it for heavy duty usage so that's why I wanted it. I agree, if it was a basic Shift Improver kit or Transpak it would be fairly easy to undo it. I just remember when I had a T-400 in my '68 Firebird daily driver. I started with RV/Towing- moved up to Street/Strip- and that winter it snapped. I forgot that when you boost the line pressure- and it's winter- bad things happen. So I don't want a severe duty kit in there. I know it's probably best to just drive it, but I was hoping to determine what is in there beforehand. I have to change the filter anyway so I guess it wouldn't hurt to open it and at least see if any check balls are missing.