ForumsBasic TrainingOnline Maintenance ManualsThe M715 Zone Vin RegistryVPW's M715 Parts ListGalleriesLinks

Go Back   M715 Zone > General Tech > Open Discussion

Open Discussion Open Discussion for all M715 series trucks

Thread Tools Display Modes
Old February 5th, 2017, 12:51 PM
whizone whizone is offline
Join Date: Jan 2017
Location: southeast texas
Posts: 2
whizone is a Soldier
Default What type of fluid for T98 & NP 200?

Hey guys new to the M715 world and wondering if anyone could advise what type of Trans & TC fluid should I use in my M715? Also where in the heck are the Trans $ TC fill ports located? Thanks like this truck!
Reply With Quote
Old February 5th, 2017, 01:45 PM
brute4c's Avatar
brute4c brute4c is offline
Grand Poobah
Join Date: Sep 1998
Location: North Central Wisconsin
Posts: 11,375
brute4c is a Soldier

Welcome to the madness!!

The stock spec is gear oil, 80W90...I run synthetic at 75W90 which helps with real cold weather up here in the great white probably can use either...

The tcase LOVES to get hot if you run more than about 50 mph with stock gearing and tire size...if the tcase overheats, it will boil the fluid...i know...with a temp gauge in the case I watched it overheat and then stopped and listened to it boil for 20 minutes...not on purpose of course...

If you intend to drive at speeds above that sustained in the Texas heat, use the best lube you can for now and monitor it for boil off...then consider changing out to an NP205...heat problems will disappear...

Just to be clear, there is no lube that will prevent the overheat problem...using a very heavy lube might give you a couple minutes of time past where 80W90 would boil before it does but thats about real help.

As far as fill location, both have screw in plugs that have a recessed square can use the square on a 1/2 inch ratchet to turn it...

Trans plug is half way up the passenger side.

Tcase is on the drivers side, low.

After draining the old, with the drain plugs on the bottom, fill to the bottom of the fill holes on the side...the amounts are listed on the Lubrication Order on this page:

More detailed info here:

Theres lots of info in the Online Maintenance Manuals page linked at the top of all the sites pages.
Lord send your Holy Ghost into our hearts and make the desire of our hearts Your Will.

Pro-choice, that's a LIE, babies don't choose to die!!
Reply With Quote
Old February 6th, 2017, 02:42 PM
jeepdan's Avatar
jeepdan jeepdan is offline
Join Date: Jul 2012
Location: Wheeling, WV
Posts: 1,384
jeepdan is a Soldier

For the transmission especially, it's best to use the older GL 4 formula to protect the synchronizers, and other brass parts.
Sta-Lube is what I used
Reply With Quote
Old February 8th, 2017, 07:56 AM
Nailhead Nailhead is offline
Join Date: Aug 2015
Location: Longmont, CO
Posts: 695
Nailhead is a Soldier

Amsoil 75-110 in the trans & 85-140 in the case. The gearbox is noisy, so I used the thicker stuff to quiet it down.
Reply With Quote
Old February 8th, 2017, 04:20 PM
md1970 md1970 is offline
Join Date: Jan 2014
Location: ne indiana
Posts: 702
md1970 is a Soldier

amsoil is good stuff
Reply With Quote
Old February 9th, 2017, 06:20 AM
Nailhead Nailhead is offline
Join Date: Aug 2015
Location: Longmont, CO
Posts: 695
Nailhead is a Soldier

Originally Posted by md1970 View Post
amsoil is good stuff
I think so. I'm going to repack the front wheel bearings with Amsoil grease, replace the hub seal, and then fill both pumpkins with their 75-90 (or whatever weight it actually is).

Their grease is amazing, but it weeps oily crap out of grease guns in hot weather.
Reply With Quote
Old June 12th, 2018, 05:39 AM
68bluegreen 68bluegreen is offline
Basic Trainee
Join Date: Mar 2012
Location: Crestwood,kentucky
Posts: 47
68bluegreen is a Soldier

check what the GL rating is modern oils will eat up the yellow metals,bress and bronze.Also the new EPA rated engine oils arenot the best for older engines . Even the diesel designated oils have had their rating changed.
Reply With Quote
Old June 13th, 2018, 12:37 AM
glendom glendom is offline
New Recruit
Join Date: May 2018
Location: Philippines
Posts: 11
glendom is a Soldier

Can't go wrong with Amsoil. A bit pricey but good quality fluids.
Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

Forum Jump

All times are GMT -7. The time now is 05:48 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
1998 - 2019

This site is owned and operated by:
M715 Zone, LLC
President: Jon Schmidt, User ID=brute4c
If you have any suggestions, comments, problems or questions, contact:

Use of this site means you understand and agree to our TERMS OF USE

Copyright Notice:
This web site is subject to the protection of the copyright laws of the United States and other countries. Except for Personal Use Only, you may not modify, copy, distribute, transmit, display, perform, reproduce, publish, license, create derivative works from, transfer, or sell any information obtained from any part of the M715 Zone website without the prior written permission of M715 Zone, LLC.

Written permission can only be obtained by contacting

Copyright 1998-2019