Shifting problems.

[MarksSC94]

Hi all. I have a 94 4.0 4X4. I don't know the tranny I have. I suspect it is a A4LD, but not sure. It is a 4 speed auto. I am having a problem that I suspect is a VB or vacuum modulator issue, but it might not be either. What happens is, it doesn't want to shift from 1st to 2nd under acceleration. I wind it up to about 3K rpm and take my foot off the gas it will shift then, but not until I take my foot off the gas. Anyone have any ideas? I any information will be helpful.

Thanks, Mark

 

[BrooklynBay]

A 1-2 shift delay is usually caused by a sticking governor. You have the A4LD. Check your modulator for leaking fluid in the vacuum hose, and with a vacuum pump to see if it holds vacuum.

 

[BrooklynBay]

Do you have this problem all of the time, or just when it is cold? Does it go away when it starts to warm up? A temperature related problem on this could be related to the governor, or bad valve body gaskets. Your VB bolts could be a little loose too. When was the last time you replaced the fluid, and filter? Do you ever have any flare ups in any other gears besides the 1-2 shift?

 

[MarksSC94]

It happens all the time. Hot, cold, warm what ever. I was hoping to hold off on any tranny work for a bit. I wanted to buy one and put all the mods I needed in it, but it looks like I will have to do a little VB work on this one. Also I read in a post were someone replaced a couple of pistons or cylenders on theirs. I was wondering what these were and where they are located. It didn't sound like they were VB parts so I was cuirous what they were. Any way, looks like I will be looking for a kit for the VB and new modulator.

Thanks, Mark

 

[BrooklynBay]

There are 3 pistons. 2 are on the passenger's side of the transmission. One is for the OD (near the bell housing), and the other one is closer to the middle (intermediate). The low/reverse piston is inside of the pan to the rear of the VB. The first 2 are adjustable, but the one in the pan is not.

 

[Glacier991]

The intermediate servo is used in the 1-2 shift. I can warn you these are buggers to access with the transmission IN the vehicle. It is doable, but it is a job I'd farm out.

Many folks lose the heat shield. Is yours still in place ?

 

[MarksSC94]

Yeah the shield is still there. I can hear when the rumble is right. So I take it the intermediate is accessable from the outside of the tranny. I am going to try to pick the kit next week and rebuild the VB. I have the tools, I just haven't messed with one in a while. I hope that all will go well. If anything I will be in better shape from riding my bike for a while. Mark