The 1947 - Present Chevrolet & GMC Truck Message Board Network

Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board


Thread Tools Display Modes
Old 10-10-2018, 04:36 PM   #1
Senior Member
SunSoaked's Avatar
Join Date: Dec 2011
Location: Yuma Arizona
Posts: 877
Nv4500 fluid-

Getting ready to do the swap. Need fluid. Obviously the OEM Castrol Syntorc is no longer available. Remaining supply is almost impossible to find and the $$$ is ridiculous. I see several aftermarket brands that are advertised as replacements:

Amsoil-Redline-Royal Purple...

Cost aside, anybody have any knowledge, experience or opinion on one over the other?
SunSoaked is online now   Reply With Quote
Old 10-10-2018, 08:19 PM   #2
Tiger Joe
Registered User
Join Date: Mar 2015
Location: South of Pittsburgh
Posts: 386
Re: Nv4500 fluid-

I’m running redline in 3 different trans right now with no issue. Used the AC delco too
Tiger Joe is offline   Reply With Quote
Old 10-10-2018, 08:21 PM   #3
Senior Member
Join Date: May 2015
Location: Alabama
Posts: 7,065
Re: Nv4500 fluid-

I went straight to the dealership to get mine....but get ready...this stuff ain't cheap...
Mongo...aka Greg

1981 c30 lq9 nv4500..
1955.1 ls3 tr6060...(under construction)(on hold)
2013 gmc z71. (daily driver)
Columbus..the 1957 IH 4x4...
mongocanfly is offline   Reply With Quote
Old 10-11-2018, 09:50 AM   #4
Registered User
v30crewcab's Avatar
Join Date: Apr 2012
Location: Chatt Tn
Posts: 604
Re: Nv4500 fluid-

amsoil is cheaper than the dealer crap.
88 military v30 crewcab shortbed
5.9 cummins, nv4500, 205
v30crewcab is offline   Reply With Quote
Old 10-12-2018, 09:47 AM   #5
Registered User
MJN's Avatar
Join Date: Feb 2000
Location: Maquoketa, Ia/ Orr, Mn
Posts: 1,397
Re: Nv4500 fluid-

Amsoil Manual Transmission and Transaxle Gear Lube 75W-90. If you sign up as a preferred customer you'll save 25% over retail, earn points towards future orders for additional discounts and get free shipping with orders over $100. I'd be happy to sign you up and be your sponsoring dealer, the cost is $10 for 6 months or $20/year.
'51 South Bend Model "A"
'52 Dodge M-37-repowered with 283 SBC
'56 Chevy 3600 NAPCO
'74 Chevy Cheyenne Super K/20-fully restored on 37's
'72 GMC Sierra Custom k/2500- in progress
'02 GMC Yukon XL 2500
'08 GMC Envoy Denali
MJN is offline   Reply With Quote
Old 10-12-2018, 05:51 PM   #6
Senior Member
hatzie's Avatar
Join Date: Oct 2008
Location: Wentworth, NH
Posts: 3,180
Re: Nv4500 fluid-

The official oil from GM and Chrysler is Castrol Syntorque with AC Delco or Mopar labels on the bottles.

I've used Torco RTF and Castrol Syntorque in my NV4500's.

Syntorque is a specialty oil for a single transmission... the NV4500... That transmission, in GM dress, ended production almost two decades ago and was mostly only used in 3/4 & 1 ton trucks in the 1990's to any large degree. Castrol can't make thousands and thousands of gallons of the oil to get the price down to Wally World pricing and there are rumors that it is no longer being produced so it will not be going down in price for that reason as well.

One of the important properties of Castrol Syntorque is the slow rate it heats up supposedly because of low friction. It also doesnt attack the oddball composite synchro rings New Venture used in these gearboxes. Torco RTF Gear Oil is a group IV/V oil. It's performance is a very close second to the Castrol Syntorque and it's still being produced. $23/qt from Summit.

The Dodge Cummins boys claim it takes 5-6 full power dyno passes to get Syntorque and 4-5 & sometimes 6 to get the Torco RTF up to 140F in the NV4500. Most other possible oils fall well short of that and neither oil attacks the synchros.
1959 M35A2 LDT465-1D
1967 Dodge W200 B383, NP420/NP201
1969 Dodge Polara 500 B383, A833
1972 Ford F250 FE390, NP435/NP205
1976 Chevy K20, 6.5L, NV4500/NP208
1986 M1008 CUCV
2000 GMC C2500, TD6.5L, NV4500
2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263
2009 Impala SS LS4 V8

RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials...Please include at least the year and model in your threads. It'll be easier to answer your questions.
And please let us know if and how your repairs were successful.

Last edited by hatzie; 10-13-2018 at 08:48 AM.
hatzie is offline   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 -4. The time now is 06:32 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2018, vBulletin Solutions Inc.
Copyright 1997-2013