Help converting 4L80e from 2wd to 4wd - Page 2 - Pirate4x4.Com : 4x4 and Off-Road Forum
 
Pirate4x4.Com : 4x4 and Off-Road Forum  

Go Back   Pirate4x4.Com : 4x4 and Off-Road Forum > Brand Specific Tech > Chevy
Notices

Reply
 
Share LinkBack Thread Tools Display Modes
Old 05-27-2017, 02:32 PM   #26 (permalink)
Registered User
 
Join Date: May 2017
Member # 760065
Posts: 3
So to kick a dead horse and drag up a old thread, here I am. Have a 01 yukon 2500 and had got a rebuild 4l80e cheap. 2wd trans so cut the shaft to the proper length but still have about a 1/4 inch gap between the np246 the case and the adapter. In the diagram above I have shaft C. Question is, that taper on the transmission output looks to be causing the transfer case to not quite slide far enough to bolt to the adapter. Am I nuts or did I miss something?
Roscoe1973 is offline   Reply With Quote Quick reply to this message
Old 05-27-2017, 03:06 PM   #27 (permalink)
blatant asshole
 
total newb's Avatar
 
Join Date: May 2014
Member # 464641
Location: trinity center ca
Posts: 11,652
What does the dial indicator say about the situation?
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
total newb is offline   Reply With Quote Quick reply to this message
Sponsored Links
Old 05-27-2017, 03:54 PM   #28 (permalink)
Registered User
 
Join Date: May 2017
Member # 760065
Posts: 3
Don't have one but the caliper says it's just a tad bigger then the i.d of the tranfer case input
Roscoe1973 is offline   Reply With Quote Quick reply to this message
 
Old 05-27-2017, 06:44 PM   #29 (permalink)
blatant asshole
 
total newb's Avatar
 
Join Date: May 2014
Member # 464641
Location: trinity center ca
Posts: 11,652
Whar about the depth.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
total newb is offline   Reply With Quote Quick reply to this message
Old 05-28-2017, 12:28 PM   #30 (permalink)
Registered User
 
Join Date: May 2017
Member # 760065
Posts: 3
Everything measured right. Ended up taking a bit off the transfer case input. Splines are long enough I wasn't worried about lack of contact area there. And.most of the thread seems to be converting too a other then stock transfer case
Roscoe1973 is offline   Reply With Quote Quick reply to this message
Old 03-01-2018, 05:13 PM   #31 (permalink)
Registered User
 
Join Date: Jul 2001
Member # 5799
Location: Bakersfield, CA
Posts: 578
Quote:
Originally Posted by Trazer75MT View Post
To answer your question about the steel sleeve crimped on. That is a 2WD only part, it seals around the driveshaft. You will find an o-ring inside it near the end. The driveshaft slips inside it, and it was used to help keep oil from leaking out the center of the slip yoke for the driveshaft.

The cup plug people have told you to replace with one that has no hole in it is correct. 2WD has a small hole drilled in that plug to spray lube at the bushing around the driveshaft. 4WD no hole in that plug, would your trans burn down if you ran around with a tiny hole in that cup plug, No.

The oil getting sprayed out of that cup plug is from the Lube/Cooler circuit. Not line pressure. I was a builder in a transmission shop for years. So I double checked all this for you in my old program I have. Go ahead and knock/pry the crimped on sleeve and wing it in the trash.
Since you seem to be pretty knowledgeable on trannys. I thought I would ask you about the o-ring boss on the stock 2 wheel drive tailhousing. I am mating an NP205 with a TH400 adapter to the 4l80E in my 2500. I keep reading that i will need to machine a groove in the adapter to accept that o-ring but if I am replacing the cup plug with one that doesnt have a hole, what is the purpose of the o-ring?
__________________
Esteban
Esteban86K5 is offline   Reply With Quote Quick reply to this message
Old 03-01-2018, 05:19 PM   #32 (permalink)
Granite Guru
 
WildWilly4x4's Avatar
 
Join Date: Mar 2003
Member # 17680
Location: Sunray,TX
Posts: 953
get the adapter from Northwest fab and save your time. the 400 to 4l80e adapter they make is probably as cheap or cheaper than machine work, and it makes everything the same length as a factory 80e/ 205 adapter. Plus it gives you room to bolt on your tranny mount, where without it your tranny mount is gonna be into the 80e's oil pan.

Edit: sorry, I guess I misread your post. Oil will still get to the back of tranny through the case drains and what not. Your tcase adapter does still need to make a seal, or oil will leak. The galley that you are plugging with the "cup" - (I used a small freeze plug from the parts store), is the oil galley that lubes the slip yoke on a 2wd trans.
__________________
'50 m38, 60, 14bolt, 4.3, 420, dana 300, 35" krawlers on trailready's/ '80 Blazer 60,14 bolt, tpi 350, th400, 205, 35" swampers

Link to my M38 build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by WildWilly4x4; 03-01-2018 at 05:23 PM.
WildWilly4x4 is offline   Reply With Quote Quick reply to this message
Old 03-01-2018, 05:40 PM   #33 (permalink)
blatant asshole
 
total newb's Avatar
 
Join Date: May 2014
Member # 464641
Location: trinity center ca
Posts: 11,652
The th400 adapter wont work without the spacer from nwf.

The pilot bore is smaller on the 4l80
The feet are forwards on the th400 adapter and wont clear the body of the trans if you machine the pilot

So either machine the adapter and completely fab some sort of new mounting system or buy the spacer and everything bolts right up.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
total newb is offline   Reply With Quote Quick reply to this message
Old 03-01-2018, 06:40 PM   #34 (permalink)
Registered User
 
Join Date: Jul 2001
Member # 5799
Location: Bakersfield, CA
Posts: 578
First time I have heard about the pilot bore. Not even sure what the pilot bore is (newb i know)

I do have a friend with lathes and mills so he will probably do it all at no cost. I was unsure why the oring was needed if the hole was being plugged but the drain back into the tranny wasnt something i thought of (again...NEWB)
__________________
Esteban
Esteban86K5 is offline   Reply With Quote Quick reply to this message
Old 03-01-2018, 07:32 PM   #35 (permalink)
blatant asshole
 
total newb's Avatar
 
Join Date: May 2014
Member # 464641
Location: trinity center ca
Posts: 11,652
The adapyer has a male lip on the trans side. The trans case has a register/recess to accept the lip. Its alignes and centers the adapter and tcase to the main shaft of the trans.

On a th400 its 4.870", on a 4l80 its 4.800, .070" smaller. There is plently of material to turn the lip down to fit the 4l80 trans but the feet of the adapter will not allow it to mate up, they hit the case and no you cant clearance the rail to clear.

The adapter from nwf relsoves 3 issues.
1 the pilot bore
2 the output shaft length (aprox .500" longer than th400 round pattern tcase output)
3 pushes the adapter back enough to allow the mount to work.


Its a fairly simply plate. .750 thick, trans 6bolt pattern, 4.800 male lip, 4.870 female register. Final thickness of the adapter is .600" on the faces. Idk how tall the lip needs to be.

Be aware that the trans bolt pattern is not symetrical. So use a gasket and mark.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
total newb is offline   Reply With Quote Quick reply to this message
Old 03-01-2018, 09:26 PM   #36 (permalink)
Registered User
 
Join Date: Jul 2001
Member # 5799
Location: Bakersfield, CA
Posts: 578
Thats some great info. Thank you!!
__________________
Esteban
Esteban86K5 is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Pirate4x4.Com : 4x4 and Off-Road Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.

** A VERIFICATION EMAIL IS SENT TO THIS ADDRESS TO COMPLETE REGISTRATION!! **

Email Address:
Insurance
Please select your insurance company (Optional)

Log-in


Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 12:54 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0 ©2011, Crawlability, Inc.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.