Sas954unner

I just finished my 3.4 swap last weekend and I've just pulled the tranny only to find the output shaft on my 3.0 tranny is 3" long and the output shaft on the 3.4 tranny is 4". I think it's preloading my pressure plate and causing my clutch to not engage properly

I'm using a 3.4 flywheel and clutch, a 3.0 tranny with a 3.0 t/o bearing
Just like everybody says to do

Any ideas?
I don't want to put this all back together with a brand new clutch to have it slip again

Sas954unner

I also just measured from the edge of the throw bearing contact ring to the end of the output shaft on the 3.0 tranny it's 3.5" and on the 3.4 tranny it's 4.0"
Something is fishy here this whole 3.0 tranny with the 3.4 clutch and flywheel idea doesn't sound so good anymore

BigBluePile

iTrader: (3)

How long did the tranny sit around?

Sas954unner

2 months definitely not a long enough time for the input shaft to have a growth spurt

aztoyman

The 3.4 shaft IS longer than the 3.0 but the 3.4 bell housing is deeper to match.

Let us know what you figure out. I'm going to be doing the same setup as you did.

Sas954unner

I am planning on putting a 3.0 flywheel an clutch on it
Whoever says the 3.4 clutch works is full of ˟˟˟˟ the throw out bearing presses against the pressure plate and makes the clutch slip

I trusted write-ups but I should've measured it when I was putting it in.

aztoyman

A lot of people have done this so maybe you missed something?

The clutch disc goes backwards of what you would see with the 22RE. Not sure if same as 3.0.

Is the fork different? Slave cylinder longer?

Let us know because there are others like me getting ready to do this.

BigBluePile

iTrader: (3)

That's not what I meant.

What's the truck doing? Tranny not engaging with motor on while its sitting on its wheels? If on jack stands with motor on will it engage and go in gear? While on its wheels motor off will it cycle thru the gears?

Did you put the clutch disc in backwards?

jd20phill

iTrader: (7)

I'm running the 3.4 flywheel, clutch, and pressure plate with the 3.0 throw out bearing and 5 speed with no issues (also using the 3.0 starter with it). Been like this for the last year and a half. I suspect that something else is causing your issues.

Sas954unner

Put a brand new 3.0 flywheel nd clutch in it and she is perfecto!

Sas954unner

With the 3.4 flywheel and clutch in my slave cylinder was compressed under pressure and the clutch just wouldn't grab.

The disk only goes in one way I don't understand why people think that could even be possible you would have to smash the disk into the flywheel with a sledge hammer just to make it fit!

I'm not saying I'm a genius but I'm pretty quick on figuring things out and diagnosing issues, so like I said the 3vz tranny's input shaft is a full inch shorter than the 5vz's tranny
I also measured from the contact ring on the t/o bearing to the tip of the input shaft and the 3vz is 1/2 shorter in that measurement as well

Once I got the 3vz flywheel and clutch I bolted the pressure plate to the flywheel
And laid it next to the 5vz flywheel and clutch and the 5vz measured a 1/2 taller (laying on the ground that is ) than the 3vz setup

I have a dual transfer cases r151 so idk if that makes a difference
BUT I CAN SAY WITH 100% CERTAINTY
that the 5vz clutch/flywheel combo did not work for me
The 3vz flywheel and clutch worked 100% perfect

Everybody says that the 5vz is a heavier duty flywheel
Although* the flange where the 3vz flywheel bolts to the crank is 3/8" thicker than the 5vz's flywheel(I know this because I had to run to the local hardware superstore to get flywheel bolts that were 3/8" longer than what I had in the 5vz flywheel)

So with all that said I would never recommend using the 3.4 clutch

Sas954unner

Sas954unner

Sas954unner

This was the engine with the 5vz clutch on it the first time around
You can see how much deeper it is

aztoyman

Well now you got me worried. I'm also running the R151F and duals with the 3.4. I already have all the 3.4 clutch stuff.

I have a 3.0 bell housing bolted to my 151. It is definitely not as deep as the 3.4 bell but, it matches the input shaft length and has the slave and fork on the right side.

I wonder what was different? I know the 3.4 is way thicker than the 3.0 clutch assembly. Plenty of people have run the 3.4 clutch with no problems though.

One thread I read, the guy said all he changed was the bell housing. He even used his original R151F slave, fork and TO bearing. Which I planned on doing.

I did see one or two threads where somebody had to remove the pivot ball from the bell housing and machine the mounting surface to drop the pivot ball down a little. But, like you, everybody jumped in and said they had no problems and never heard of doing that.

I can hardly wait to see how mine is going to work out. Still recovering from back surgery. Friggin 10# weight limit is stopping me from doing ANYTHING.

aztoyman

OK, I'm running into the same problem as the OP. Well, maybe. The TO bearing definitely has some pressure against the clutch. I can still spin it by hand though.

I have the engine hanging on the picker. I bolted up the fresh flywheel and new OEM AISIN clutch. I have the 3.0 TO bearing, 3.0 bell housing and the 22RE/3.0 slave.

The 3.0, 22RE, and 3.4 forks all look the same. I even tried them all to be sure.

I put the bell housing on the engine without the trans so I could see what was going on. The TO bearing is riding on an alignment tool to keep it centered.

I compressed the slave completely in and it will allow the TO bearing to NOT have pressure against the clutch ONLY WITHOUT the rubber boot on the slave.

The rubber boot on the slave will hold the TO bearing against the clutch even without the rod in the slave.

The rubber boot for the fork also will hold the TO bearing against the clutch even without the slave installed.

There is enough pressure on the TO bearing to keep it spinning constantly. I don't think it is enough to slip the clutch but, I think it will reduce the life of the TO bearing.

If I set it up as is, I will need a return spring to take pressure off the TO bearing.

Or is it normal to keep the TO spinning?

uniformFoxtrot

Dudes is it common to use 5vz flywheels when doing the 3.0 to 3.4 swap, I'm going to be needing a clutch soon and but would hate to run into problems for lack of knowledge should I switch one for the other? I thought the 3.0 bell housing fit the 3.4 no problem?...

Sas954unner

Once I put the 3.0 flywheel and clutch in I had play in the t/o bearing. Enough so that I could feel the play in it.
From my personal experience I would just use a 3.0 flywheel and clutch to avoid any headache.
Unfortunately I have a dual transfer cased transmission an had to learn the hard way yanking that heavy bitch out by myself.

aztoyman

OK, I'm going to put this to rest. This bugged me so much I stuck the 3.4 bell housing on and set it up with the 3.4 TO bearing to compare.

The 3.4 slave has a stronger spring inside it than my 22RE and 3.0 slave, so it puts pressure against the TO bearing.

About the same pressure as I have with the 3.0 bell housing and 3.0 slave.

So it must be normal for the TO bearing to ride against the clutch. Just not enough to allow the clutch to slip.

The TO definitely rides against the clutch but I can still turn it by hand. Not that much load. I was worried it would wear my TO bearing out fast.

After more searching I found out early trucks had a return spring and adjustment at the fork. Looks like 85 up TO bearing always spins. Spring in slave keeps a little pressure on so parts don't fall out or rattle.

Sorry if I worried anybody and I hope this clears it up.

Sas954unner

I went a different route and used the 3.0 bell housing because I wanted to keep the slave cylinder on the opposite side as the exhaust