4l80e swap?
 

putting a 4l80e in my truck had 350 turbo what cross member do i need

Re: 4l80e swap?
 

Stock cross member will work, it needs to be measured to the length of the new tranny, then re-drill the frame for that position. You will also need a 4L80e mount and bit of fabrication to have it fit the stock x-member.

I'm doing the swap from a th400 to a 4l85e super-matic the end of next week, I'll get some pictures up to show off my "electrician trying to play mechanic" skills, you can learn from my mistakes...

Re: 4l80e swap?
 

well i don't mind buying aftermarket cross member would in fact rather do so then trying to mod old one and having it look like sh**.cause im no fabricator

Re: 4l80e swap?
 

There are a few aftermarket cross members out there ranging in price from $70.00 to $270.00 they are all basically the same part give or take powder coating, painted or raw. Thing is all those that I have seen are advertised as being for a TH350, TH400 or 700-R4 none of them are specific for a 4l80e, or 4l60e.
Also the tranny mount itself is a different piece for a TH's and a 4L's, I think one is two bolts to the tranny and the other one bolt to the tranny?
Anyone else out there having done this conversion with an aftermarket x member what did you use and what was the solution?

Re: 4l80e swap?
 

I am curious about how the speedo is done.

Re: 4l80e swap?
 

I pined over this as well going from a mechanical to an electric speedometer. The options I found were:

New tranny tail shaft housing $400 then adding a drive gear, sleeve and driven gear, sleeve retainer, and bolt added another $250, So $650 total-ly insane :eek:

Cable X makes an electronic to mechanical tachographs that can also do the trick for $350

A specially machined output shaft that allows you to use a stock TH400 gear in a 4l80e A few hundred bucks for that also

However I believe that all of these options require a Electronic Ratio Adapter to adjust for tire size or gear swap another $170.

Needless to say the price is steep for something that should be so simple, then it hit me, two birds with one stone for about $200... And the gauges are an upgrade that I have been wanting to do for some time now and this speedo just plugs into the 4l85e harness, simple is as simple does...

Re: 4l80e swap?
 

Not trying to hijack, but will a 4L80E fit a low hump cab? I need to know... and I hope the answer is yes.

Re: 4l80e swap?
 

never thought about that but don't see why it wouldn't

Re: 4l80e swap?
 

Mine fit fine. And you don't need to modify the crossmember at all, just move it back and drill new holes in the frame, super easy. You also don't need the 4l80 mount, use the 350 turbo one it will bolt directly to the trans, you just need to use the metric bolts from the 4l80e

Re: 4l80e swap?
 

good stuff thanks

Re: 4l80e swap?
 

Thanks for the info nova...

Re: 4l80e swap?
 

How do you "control" it?

Is there a "stand alone" computer kit for them?

Re: 4l80e swap?
 

yea there is thats the downfall its 1100 dollars but i would have that much in a 700r4 that wouldn't hold the power i want

Re: 4l80e swap?
 

Wow, that is pricey!!!

It's only money though, right?

Re: 4l80e swap?
 

is there not another option for controlling it other than $1100

Re: 4l80e swap?
 

I have heard of guys using computers out of 90-93 chevy diesel pickups that had mech injection and 4l80

Re: 4l80e swap?
 

packers05 is correct. 91 - 93 diesel trucks, 6.2 N/A and 6.5TD, had a stand alone ECM just for the transmission since the engine was no computer controlled. In '94, the engines got computers and it was integrated.

Re: 4l80e swap?
 

I checked car-part.com and they have plentey
91 - 93 diesel trucks Trans only computor

from $45 to $100

Re: 4l80e swap?
 

that seems a whole lot more reasonable

Re: 4l80e swap?
 

my stock X-member is used along with no drilling on frame. I did use the 4l80 trans mount b/c it is slightly offset and works better.

You will need a trans controller, and it's $$.
I am using an Abbot Cable X unit to run my stock speedo from the PCM. (I can ship those for $300)

I have a low hump cab and plenty of room.

Re: 4l80e swap?
 

I wondered about aftermarket speedos made for the electronic transmissions.That`s what I`ll do.My 4L80E is out of my`91 Diesel 3/4t Suburban.If I don`t resurrect that the trans goes in my`72.

Re: 4l80e swap?
 

ok so i just found out mine is a 93 so what do i need for this stand alone computer does anyone have pictures or info