Ever since I got my engine swap, it seems my tranny (700R4) revs between 2nd and 3rd under load. If it's at about 1500rpm or less during the shift (or going down hill), it's fine, but if I'm pulling a hill, or accelerating at about 1700 or more, it seems 3rd doesn't engage right away, and it'll jump between 200-500rpm depending on how hard it's being pushed. Once 3rd engages, it's fine again.
Is this a clutch plate issue, valve body issue, or something else?
The tranny does have about 130,000miles on it, and I do intend to but a new, and stronger one when I get the cash.

Thanks for any replies.

 

This is a common issue with the 700R4's. There are several areas that can be changed to reduce the flair on the 2-3 shift. A larger servo is recommended, IE: the 'Vette servo. This is accessed from the outside of the trans, right hand side. Easy to do. There is a site around that shows step by step w/pic's how to do this.

A larger boost valve will help. This is under the pan and easy to change out. With it under the pan it's a good time to change the filter and fluid.

This last area is a little more difficult as the valve body needs to be R&R'd. This would be to open up the 3rd apply feed hole. There is a couple of posts by Pro-Built that shows where and by how much to open up that feed (along with a couple of others).

Al.

 

So, this is a common occurance? I thought my tranny was going . Well, if this is supposed to happen (that is, nothing is failing), I feel a lot better.
I'm still going to get a new tranny later, but I guess this means I don't have to baby this one as much as I was.
Thanks for the reply.

 

Yes, a common occurrence, and a common failure mode. The more you run the trans in this state the faster it will go out. The flair is actually burning up the 3/4 clutch pack. To help prevent the issue and make the transmission last longer. . . that is what I addressed.

If it keeps flairing on the 2-3 shift it won't last much longer.

Al.