4L60/700R4 4x4 case stubby transmission for rods..

wayne petty · December 29, 2012, 08:59:40 PM

just curious if a stubby 4L60 or 700R4 could be created using a 4x4 case. creating a backing plate like is used on stubby powerglides...

so people with the need for short transmissions could use the overdrive transmission

i know this is a real nitch market.. but i know there are several members here that might have already done it..

enjenjo · December 29, 2012, 09:24:37 PM

Yes, it can be done, but it takes more than a plate to do it right. You have to create a support for the yoke, that will accept a bushing. Not a big deal, but necessary.

wayne petty · December 29, 2012, 11:06:49 PM

is there any ATF flow back there to lube the bushing or would it need to be something like a double row wheel bearing to support the yoke... allowing it to slip in and out and be torsionally stable... allowing torque to be applied to any side as the yoke transitions through its variations.. or would it be better with a fixed yoke.. and a ball bearing.. no slip in and out.. as the slipping in and out would cause wear between the yoke and the inside of the bearings needing only an slip joint in the short drive shaft that would make it easier to install and remove anyway..

this would probably require either center drilling and tapping the output shaft .. or machining a longer output shaft for the threaded area...

end play adjustments might be critical.. or a compression spring on the output shaft or bellville washers to allow the inner bearing to be cinched in tight.. but allowing for slight case expansion.. that would require running the transmission on an engine driven dyno with a dial indicator to check for case length expansion from cold to hot..

wow... i just keep digging the hole deeper and deeper don't i..

ok... how about a case and a shaft end measurement difference between a stubby power glide and what would be a stubby 700R4 4x4 case...

or should i think about the 4L65E or what ever version is used in the C5 and C6 corvettes as the rear diff is bolted directly to the back of the transmission..

say... wait.. corvette C6 models have 6L80E six speed transmissions.. HMM... how much longer is that.. i know its NOT CHEEPER.. i see that it will take 600 foot pounds of torque..

Warpspeed · December 30, 2012, 04:48:31 AM

Should be possible, there is auto transmission fluid back there, it is not sealed off from the pan.
If you wanted to pressure lubricate a slip yoke bearing, a bit of fluid could be stolen from the transmission cooler lines to do it. It will drain back easily to the pan no problem.

I have a 4x4 4L60E sitting on my workbench right now with the transfer case off.
Output splines are 27, same as normal 4L60.
4X4 output shaft is 4 5/8" long.

Anyone know how long a normal 4L60 output shaft is ?

All you would need would be a flat plate to bolt onto the back of the transmission with four holes (early 4L60) or six holes (later 4L60), and a big fat tube welded onto it to hold the slip yoke bearing and rear oil seal.

Or maybe a very short rear gearbox extension off some other gearbox with a simple flat adapter plate may be possible ?

You would also need to fabricate up a suitable road speed sensor.
Theoretically that could be anywhere on the tail shaft, or maybe one of the ABS tone wheels could do double duty for that ??

Seems quite practical to do, just needs a bit of research.

Crosley.In.AZ · December 30, 2012, 08:31:32 AM

The governor gear on a 700 - 4L60 trans would splash oil around. Plus depending on year of case, GM drilled a hole for pressure spray aimed at the tail housing area when electronic speed-O were used.

The mechanical speed-O gear also splashed - spray oil towards the tail housing. When electronic speed-O was introduced , GM added the small spray hole in 700r4 - 4L60 trans

On a 4L60E trans, there is a pressure spray hole aimed at the tail housing , since the governor and speed-O gears were removed. ALL trans case have the hole

wayne petty · December 30, 2012, 11:22:12 AM

Quote from: "Crosley"The governor gear on a 700 - 4L60 trans would splash oil around. Plus depending on year of case, GM drilled a hole for pressure spray aimed at the tail housing area when electronic speed-O were used.

The mechanical speed-O gear also splashed - spray oil towards the tail housing. When electronic speed-O was introduced , GM added the small spray hole in 700r4 - 4L60 trans

On a 4L60E trans, there is a pressure spray hole aimed at the tail housing , since the governor and speed-O gears were removed. ALL trans case have the hole

but i was thinking about a 4X4 case... not the 2wd case... as i don't think but, i could be wrong that these no fluid past the transfer case adaptor..

Crosley.In.AZ · December 30, 2012, 11:51:34 AM

Quote from: "wayne petty"
Quote from: "Crosley"The governor gear on a 700 - 4L60 trans would splash oil around. Plus depending on year of case, GM drilled a hole for pressure spray aimed at the tail housing area when electronic speed-O were used.

The mechanical speed-O gear also splashed - spray oil towards the tail housing. When electronic speed-O was introduced , GM added the small spray hole in 700r4 - 4L60 trans

On a 4L60E trans, there is a pressure spray hole aimed at the tail housing , since the governor and speed-O gears were removed. ALL trans case have the hole

but i was thinking about a 4X4 case... not the 2wd case... as i don't think but, i could be wrong that these no fluid past the transfer case adaptor..

you are wrong. cases are the same in the back end 4x4 or not.

T-case Adapters are open, the t-case has seal in front contain & separate the trans oil from t-case oil on GM applications... actually a double lip seal design. One lip faces each direction. In replacement you use 2 seals against each other

Corvette cases were different depending on year.

Most Mopar applications the t-case adapter seal off the trans oil, no gasket between the adapter and t-case. T-case has seal in front too... Often we see DIY folks come in with Mopar 4x4 trans problems and they sillycone up between the t-case and adapter , when there needs to be a hole open there for expansion of air and such stuff.

wayne petty · December 30, 2012, 01:18:09 PM

thanks... i just was NOT sure as i don't get to split transfer cases off automatics often...

so would it be possible to create a plate for the back of a 700r4 to make it a stubby overdrive??

Warpspeed · December 30, 2012, 02:47:33 PM

Just had a look at the back of my 4x4 4L60e and it definitely has the oil spray hole.

Tony is right, the whole rear housing is fully open to transmission fluid, the oil seal is located in the front of the transfer case.

Should certainly be possible to bolt a stubby housing onto the back of a 4x4 box.