GaryB148

I have a '96 I30 auto with the VLSD and 70K on it that I bought about a month ago. I took my first long highway trip with it last week and was kind of surprised when watching the tach move around as the car down shifted while hitting hills on the highway at about 80 mph.

When I had cruise control engaged along with OD, the engine would spin at about 2800 RPM at 80 mph. When I came to a steep enough hill to require downshifting, the tranny would pop the rpm to 3000 for about 3 seconds before downshifting and jumping to 4000 rpm (still at about 80 mph). I found the shift accompnying the change to 4000 rpm to be pretty harsh, and consequently started manually popping the car out of OD at the base of hills and then re-engaging the OD manually at the top of the hill so that the tranny wouldn't have to make the downshifts under heavy load. The wierd thing was that the RPMs would jump straight to 4000 when I disengaged the OD manually, but when I re-engaged the OD, the tranny would first drop the RPM to 3000 for a few seconds and then drop back to 2800 (all at 80 mph still).

My question is, what is going on with the 2800 - 3000 rpm jump? Is this some feature of the VLSD or electronically controled tranny? I thought one possibility was that at 2800 rpm I was in 4th (OD), at 3000 I was in third, and at 4000 I was in second, but I can't believe third and fourth are spaced that close together.

Anyway, I love the car and have downloaded a lot of great info from this site, my thanks to all. I don't think there is anything wrong with my tranny but am curious if someone can enlighten me regarding the shift pattern and rpms I'm seeing. Thanks.