700R4 pan clearance

[VA1983cj7]

I have recently completed a SBC/700R4/Dana 300 swap in my 83 CJ7 . I am now faced with the common problem of front drive shaft clearance with the 700R4 pan. My front shaft is a 1.25” pencil shaft. That was the only diameter that would fit. At its closest point, the shaft is only 1/16 inch from the pan.

Some solutions include:
1. Offset the motor towards the driver side. (Done - I used the M.O.R.E. motor mounts)
2. Go with a two piece drive shaft using a pillow block. (I’ve read there are vibration issues above 20MPH)
3. Increase lift. (This is not attractive to me since I have a brand new Skyjacker 2 ½” lift kit already installed – should have gone with 4” – hind sight. Doing an SOA mod would be a last resort for me)
4. Flip the Dana 300 and go with a driver side drop. (Too late for that since my Dana 30 has all new Warn hubs and axles)
5. Modify the tranny pan.

So I have a couple questions…

What would you say is the minimum comfortable clearance between shaft and pan?
How much lateral movement of the shaft can be expected during hard wheeling?
Has anyone modified the 700R4 pan for clearance reasons?
If so, any tips on how to go about moding the pan?
What about splicing in say a ¾” solid bar in place of the 1.25” tube where it passes by the pan? Granted, that would only gain you a quarter inch of clearance. Good or bad Idea?

I’m very interested to hear how you guys dealt with this clearance issue.

 

[Old Dog]

IMO splicing in a smaller dia.bar would be a bad idea.
I run a th350 and only have about 1/8" clearance, no problems with it.
You forgot one other option, clock the tc up a little, that will give you some more room, as it will move the driveshaft away from the pan some.

 

[VA1983cj7]

Thanks for your feedback Old Dog.

I kinda thought going with a smaller diameter was not a good idea.
Glad to hear your 1/8" clearance has presented no problems. Does that mean that lateral movement of the shaft is minimal when on the trail?

I guess I'l try some easy wheeling on the beach and see if I get any rubbing.

Thanks for the other suggestion of re-clocking the TC up one notch.

Anybody else running a tight clearance without any problems?

 

[CJaredo7]

Hey guys, I'm interested in finding out some more on this myself, I'm getting ready to put a 5.3L and 4L60E (electronic controlled 700r4) in my CJ7 ... I'd like to know how much lateral movement is being experienced in this situation... I will only have about 1/4" of space between my front shaft and the tranny pan...and wanted to know if that would work ok or not.

I have a 4" suspension lift, 1" body lift...and I've clocked my Dana 300 Transfer Case to where it's "almost" flat... modified my stock skidplate/crossmember to where it doesn't have that low hanging section where the 300 used to hang down. I have moved my motor over 1-1/2" to the drivers side to give it some more room for the front shaft. Hoping you all can provide some more information on this subject!

Thanks in advance,
Eric