4l80 front end clearance

[388 Vega]

I have .007 " rear play, am using the sonnax roller front hub and with the .057 pump shim, fwd end play was .012, I sanded it down to .055" and now have about .017" which i am happy with ( trans sitting on output shaft on the ground) .
While checking stator bushing fit with the pump and overrun/ shaft on the bench, I saw how close the overrun was to the pump and measured .011" from the overrun to the pump machined surfaces - is this something to worry about and should I go with the .072" select and try to get my clearance elsewhere ?
Also can you double up pump to case gaskets to pick up .015 +- clearance ?

Also is it normal for the input shaft when installed into the pump to have noticeable play vs the tighter stator support end ? I am under the impression that the rear bushing should be good to go as is vs having to line fit the stator support to the .001 - .0015" , is this correct ?

 

[clinebarger]

The Input Shaft floats in the Overdrive Carrier, You must take up the slack before a actual front end play measurement can be obtained.

The distance from the Overrun Clutch Housing to the selectable Stator Thrust IS the front unit end play.

Do not double the pump to case gasket, Use a thinner Stator Thrust to obtain .005" greater than the Rear Unit End Play....So you need .012" Front Unit End Play.....Though .013" or .014" would be OK.

 

[388 Vega]

guess I worded that wrong, I was referring to radial play with just the shaft stuffed into the pump laying sideways. I was just making sure I had no binding of the bushings and noticed there is a slight bit of play on the big end vs the stator support tube.
I am using the thinnest select I had in the kit (.057") sanded down a couple thousands and am at .010" over my rear numbers.
With the shaft/overrun in the pump while on the bench is where I noticed how close the drum is to the pump ( .010" from drum to one of the machined "pads" on the pump) and was wondering is there a point you have to watch for when going with thinner selects in that spot.
I found a wrap or two of .020" safety wire behind the input shaft circlip takes that slack out for checking fwd play - just have to safety wire a reminder tag to the bell housing to remove it afterwards

 

[clinebarger]

So you're referring to the rear Stator Bushing? I've seen worn Input Shafts cause play at that bushing, But out of spec bushings are an ever increasing issue in the industry, GFX & Seal Aftermarket make most of the generic bushing kits & they're the biggest offenders.

Durabond 8661614 is my preferred bushing but good luck finding one, Kits TK-4A & TK-4A-HP are also near impossible to find. I've been ordering & returning bushings 'til I get one that works!

You start sanding down the thinnest selective & you really need to watch for clearance issues, But .010" is good as a mile.

 

[388 Vega]

Yup that's the one.
None of the shafts had any scoring or wear marks on them, a few black shadow "smears" on the 4th and direct/fwd steels but the frictions were all perfect throughout .
I probably could or should have left all the bushings "as is" but since they came with the Jakes kit- the rear stator play is very minimal just noticeable comparing to the front bush.

Is sleeve/ valve assy in the sonnax 34200-01K boost valve kit basically functioning same as stock and not increasing line pressure like the LB1 kit ?
I installed the -01 kit and am going to use Jakes pump spring but want to make sure I won't be adding more pressure than required. I think his spring is good for 190lbs with the stock valve ?
My rig weighs 14k pounds and just shy of 500ft/lbs of torque with the 8.1 motor so I went ahead with the dual feed - should I delete the 3rd accumulator and go maybe .100" on the orifice size? Was looking at .086" for 2nd, and .082" for 4th if that sounds right by you. Kinda hard to weed thru the mods as far as what is right for my big pig vs the go fast guys.
Also big thanks for all the information over the years you have put out here ! For the most part I was able to figure out everything with hours of searches and minimal call outs with dumb questions.

 

[clinebarger]

Ever thought of a Allison 1000 conversion?

I would delete the 3rd & 4th Accumulators with .093"-.099" 3rd feed orifice when dual fed. Dual Feeding will slow down Reverse apply.

If you liked the shift feel before....Leave the other orifices alone.

What went wrong in this unit?

 

[388 Vega]

Did consider the Allison but the 4l80 ( along with the 8.1 vortec ) was literally a bolt in deal- the P30 chassis already had the extra holes drilled in the frame so all I had to do was slide the cross member back and everything lined up, used Summits adjustable trans mount and shorten drive shaft.
Nothing wrong with the unit other than the internal conditions were an unknown- was an RV salvage yard 1995 4l80 with 21k miles claimed on it , I installed it and drove a few miles to make sure the everybody was playing nice as far as electronics and programming then pulled the trans to go thru it. Seeing the unit didn't have the parking pawl installed I knew it had to have come out of a 16k pound or heavier rig so having been on a tow truck hook once a trans issue I didn't want to chance anything. Being held hostage $3900.00 for the th475 overhaul (and in 2015 dollars) will do that to you lol.
Opened it up and the unit really was clean with almost no wear other than some black "smear marks on some of the steels .
Just trying to give this guy a fighting chance to live in it's new home

 

[clinebarger]

No sane mechanic likes to work on RV's, I myself have no room to work on one.....But I wouldn't quote a "Go Away Price" either.