[Gatuncrocs]

Update;

I decided to install everything per the instructions on the transgo kit except I didn’t drill the TC holes, or notch the body or grind the switch valve. I also installed all the sonnax parts I listed above.

I took it for a drive today & it drives pretty much like it did before. Perhaps a bit more crisp changing 1-2 gears but 3-4 feels the same. I was expecting something more exciting. But if it helps my transmission last longer, its all good.

I haven’t checked the line pressure yet. I’ll do that still.

 

[Dynamic]

Did you install the Sonnax manual valve?

 

[Gatuncrocs]

Did you install the Sonnax manual valve?

Yes.
I installed the sonnax manual & pr valve.
I did everything according to transgo instructions except for the holes for TC lockup, notch & switch valve grinding. I also opted to not install TV green spring, or the gold spacer.

 

[Dynamic]

OK. You don't need the notch if you use the Sonnax manual valve. The green TV PR spring is too long, and doesn't work well at all with a TTVA. You're better off with the OEM spring anyway.

The gold spacer is a band aid for a problem that one of the mods in that kit may or may not introduce. Some do, some don't.

 

[Gatuncrocs]

OK. You don't need the notch if you use the Sonnax manual valve. The green TV PR spring is too long, and doesn't work well at all with a TTVA. You're better off with the OEM spring anyway.

The gold spacer is a band aid for a problem that one of the mods in that kit may or may not introduce. Some do, some don't.

Cool. I guess I did things right then. I also installed the transgo tf-boost kit for worn boost bores, because the kit recommended it.

I just expected more of an improvement in shifting characteristics. 1-2 feels fine but 3-4 is still pretty mushy. 50mph + when the TC locks in is when it feels best.

What’s the best port to use to test line pressure? Rear servo, front servo, governor, accumulator or overdrive? I bought a kit to test the pressure so I might as well do it.

 

[Dynamic]

Yeah, for the effort and near-permanent modifications (it takes a little doing to reverse a Transgo kit) you have to put out to install it, the results are fairly lackluster.

The accumulator port will be the most useful to you.

 

[Gatuncrocs]

Yeah, for the effort and near-permanent modifications (it takes a little doing to reverse a Transgo kit) you have to put out to install it, the results are fairly lackluster.

The accumulator port will be the most useful to you.

Thanks!

Ok, I just checked it. In Drive or 1st or 2nd it’s at 67.5 psi. In N and reverse and P it’s at 0psi.

Is that what’s it’s supposed to be?

 

[Dynamic]

That's quite low for a Transgo PR spring setup. I don't get too hung up on idle line pressure (I'm more interested in pressures under different amounts of load), but that's pretty low.

You'll only see pressure at the accumulator in forward gears.

 

[Gatuncrocs]

That's quite low for a Transgo PR spring setup. I don't get too hung up on idle line pressure (I'm more interested in pressures under different amounts of load), but that's pretty low.

You'll only see pressure at the accumulator in forward gears.

ok, I just took it for a drive with the pressure gauge attached and it went up to around 115psi. That’s driving normally, throttle about 50% up to 70mph.

I don’t think I can adjust the pressure adjustment screw anymore…it’s pretty much screwed in all the way.

 

[Dynamic]

Yeah, something is screwed up. That's a very low number, and you shouldn't have the PR adjuster screwed in at all.

 

[Gatuncrocs]

Yeah, something is screwed up. That's a very low number, and you shouldn't have the PR adjuster screwed in at all.

The PR adjuster is adjusted according to the transgo instructions….with the spring adjuster flush against the inside edge of the retainer…which is basically screwed all the way in clockwise. Screwing it in takes pressure off the spring & screwing it out applies more pressure. So what direction increases line pressure?

Right now mine is just like in the picture from the instructions.

 

[Dynamic]

OK. That is the minimum setting. But you should be seeing quite a bit more line pressure than you are, even with it backed off all the way.

 

[Gatuncrocs]

Ok, so I have room to adjust, that’s good. Someone earlier said Transgo wants 75psi at idle which means I’m close at 67.5psi…. Maybe just turn the screw two turns counter clockwise?

I was expecting more like 80-90psi to be honest, since stock is 55-60. Maybe my valve body is worn out? It does have 260,000 miles on it.

 

[Dynamic]

Yes, there's room to adjust, but you shouldn't have to. There seems to be something else wrong. There are several elements that control line pressure besides the PR spring. It sounds like something didn't get put back together right.

Don't worry about pressure at idle. Get it operating in a proper range under load. You should see 170+ at WOT with the boost valve on.

 

[Gatuncrocs]

Yes, there's room to adjust, but you shouldn't have to. There seems to be something else wrong. There are several elements that control line pressure besides the PR spring. It sounds like something didn't get put back together right.

Don't worry about pressure at idle. Get it operating in a proper range under load. You should see 170+ at WOT with the boost valve on.

Well, I’m pretty sure I got everything back together properly. I went over it several times. Could it be a problem with the pump perhaps? I know this transmission was rebuilt right before I bought it. Since it’s shifting properly, is it really likely there’s a problem in the VB?

 

[Dynamic]

Well something is not happy in there. That would be low pressure on a stock valve body. Might be time to retrace your steps.

 

[Gatuncrocs]

I went on another test drive. At WOT I’m getting 155psi

I’ll tear the VB down again I guess. What are the first things you’d look for?

 

[Gatuncrocs]

I just pulled the pan and noticed something odd. My valve body has a 3rd gen governor pressure sensor on it. There is also an adapter from 4th gen plug to 3rd gen plug. I thought my model year is supposed to have the 4th gen? Take a look at the pic. I bought a new sensor, but it’s the 4th gen. Did some 2004.5 trucks come with the 3rd gen sensor?

 

[Gatuncrocs]

Well, I installed the 4th gen sensor (plastic one) & went for another test drive. Still 70psi at idle and 150psi at WOT. And now it seems like it has shuttle shifting between 2-3. I guess the 3rd gen metal sensor is better. And I still don’t know why my pressures are low. Tomorrow I’ll tear the whole VB apart again and see if something went in backwards or something.

 

[Gravel]

In your first post, 4th picture, there’s a spacer that says it’s to prevent 2-3 shuttle shifting. Did you install that spacer?