4L80 Driveshaft Measurements

We are in the process of replacing a 6.2 / 3L80 with a 6.5TD / 4L80, and there are many modifications that are required. This post is solely about driveshaft lengths. Measurements are from center-of-cup to center-of-cup.

Rear Drive Line: 25 1/4 in.

Front Intermediate Drive Line: 32 7/8 in.

Updates in Progress

Due to unforeseen issues, we have been unable to update this site since May, 2019. There has been considerable more information and pictures gathered, and we intend to update this website fully by the end of October.

We are now in the process of updating the final information from the M1038, and are currently in the process of repowering an M998 with a 6.5TD removed from an M1114.

Please feel free to email us with any comments or requests.

Initial Start Up

On Thursday, April 28, 2019, Michael Grundman helped bleed out the fuel system by pressurizing the tank. After successfully getting fuel out of the filter drain, and then the bleed valve on top of the main filter, we gave the engine a “bump,” and it lit right up.

The glow plugs were not attached, and ambient temperature was around 65 degrees, but we were happy that it lit up that nicely. This video was taken several days later. You can hear the “click” of the control box, and the engine light up instantly.

M1038 Project: Undercoating

We are re-applying the rubberized undercoating to the M1038, because we plan to run it in the desert, and there is usually more salt in the desert than you might think. Since the body is off anyway, we are re-applying rubberized undercoating to the entire underside. CARC 686 substitute is being applied to all exterior surfaces.

Note: we applied Rapco CARC substitute 686 Tan (FS 33446) to the firewall and front areas. The remainder of the vehicle remains the 3 color camouflage at this time. As a further note, we applied Behr paint in 33446 to the container on the left side of the picture. The colors are a perfect match with each other. (Pictures were taken at different times and different light, but they are identical colors)

M1038 Project: Winch Installation

A M1038 without a winch is essentially a M998. There was no winch on the 1038 when we started restoring it.

Jess Jaynes, owner of High Angle Driveshaft (formerly in Paradise, now in Chico) supplied us with a M1038A2 winch, which installed easily.

Unlike the M1038 and the A1 variant, this winch mounts on the frame and does not use frame extensions (as are visible in earlier pictures of the chassis). A main benefit is that the approach angle is not as reduced as with the extended frame, leaving the approach angle very close to that of the M998.


M1038A2 Mile Marker hydraulic winch installed.

Powertrain Finally Arrives

After several mishaps by the shipper, the powertrain finally arrives. Damaged in transit was: fan, oil pan, alternator fan guard, and transfer case cooling lines.  On the good side, other than the damaged parts, everything looks good otherwise.  At least its finally arrived.