Old Getrag 5spd

Mopower

Well-known Member
The wisdom and experience of guys on this forum has taught me alot when it comes to these older trucks. Apparently the Getrag 5spd in the early Dodge diesels was a little on the weak side. I was told a nut backs off while hauling heavy loads in 5th gear. Is there a modification, part, or fix that will prevent this?
 
The 5th gear issue your talking about is with the NV4500 5 speed. Its not a big deal, and relatively easy to fix. Get the updated nut and gear. Install with red locktite. Torque to 300ft-lbs.
I never owned a Getrag truck. The Getrag 5 speed was in trucks from 1989-1993, Cummins ram 250 and 350. I heard there is a lubricating issue with them. Overfilling by 1 quart helps that tremendously I hear.
Because the Getrag was only used for 4 years, for quite a while there was no parts support. I would pick a NV4500 over a Getrag anyday as they are more reliable and cheap to overhaul.
 
I'll overfill mine with some good oil and cross my fingers. It's got 160,000 miles on it & probably won't haul over 14,000#. Just hoping to make it live a while. Maybe I'll keep an eye out for a NV4500 or another replacement.
 
Don't know much about getrags, because when I bought my 91 Cummins, it already had a nv4500 in it. The previous owner said he got tired of dropping the getrag out of it and put this in the last time. No more problems.
 
What year is it, and do you have the 3200 RPM governor spring?

The NV4500 swap is a little more involved than bolting the other transmission up. It takes the flywheel housing and starter from the 94-98 trucks as well.

The 6 speeds don't have any trouble with 5th and 6th gears coming apart.

If you have any questions about an old square-body truck the guys at the DTRF can answer it.
Deisel Truck Resource Forum
 
Like another post said, it"s the 4500 that had the 5th gear nut problem, not the getrag. When I worked for a dodge dealership we welded the nut on. The updated nut and locktite would still come loose under heavy use. I have a 1993 with 250,xxx hard miles on it and know of several more 1st gens with half a million or more and non have had a trans problem. Keep it overfull with quality lube and go.

Casey in SD
 
(quoted from post at 04:30:44 03/04/14) What year is it, and do you have the 3200 RPM governor spring?

The NV4500 swap is a little more involved than bolting the other transmission up. It takes the flywheel housing and starter from the 94-98 trucks as well.

The 6 speeds don't have any trouble with 5th and 6th gears coming apart.

If you have any questions about an old square-body truck the guys at the DTRF can answer it.
Deisel Truck Resource Forum

Correct, you need the adapter plate and starter from a 2nd gen. Not a big deal.
The 6 speeds do have issues towing in 6th gear. NV4500 does not have a problem towing in 4th at all. 5th in a 6 speed and 4th in a 5 speed are both direct drive.
REAL medium duty transmissions such as a RTO 6610 would handle towing heavy in overdrive every day of the week. But any trans that comes in a pickup truck cannot. Sure, NV4500 may have the weakest overdrive, but the others are not much stronger.

you can tow heavy so long as you dont have to apply more than stock power levels to overdrive. For example, if I have to apply more than 20psi of boost for more than 15 seconds, I downshift to 4th.
 
(quoted from post at 05:08:20 03/04/14) Like another post said, it"s the 4500 that had the 5th gear nut problem, not the getrag. When I worked for a dodge dealership we welded the nut on. The updated nut and locktite would still come loose under heavy use. I have a 1993 with 250,xxx hard miles on it and know of several more 1st gens with half a million or more and non have had a trans problem. Keep it overfull with quality lube and go.

Casey in SD

When you welded it on, I assume you did this with a TIG welder?
I've heard that either they work well welded, or you have disasterous results.
 
Correct, you need the adapter plate and starter from a 2nd gen. Not a big deal.
The 6 speeds do have issues towing in 6th gear. NV4500 does not have a problem towing in 4th at all. 5th in a 6 speed and 4th in a 5 speed are both direct drive.
REAL medium duty transmissions such as a RTO 6610 would handle towing heavy in overdrive every day of the week. But any trans that comes in a pickup truck cannot. Sure, NV4500 may have the weakest overdrive, but the others are not much stronger.

you can tow heavy so long as you dont have to apply more than stock power levels to overdrive. For example, if I have to apply more than 20psi of boost for more than 15 seconds, I downshift to 4th.

so my o5 dodge should have come unglueded pulling a 26 ft rv over east side of eisenhower with the tranny in 6th and the cruze set on 78?
 
I think a 13 speed double-over would be good. A gear for any speed limit yet be able to skip-shift easily when not loaded. Not sure there's one that would fit under a first-gen though.
 
I think the guys answered your questions below. Just saying I have a 91 with the getrag in it. When we got it my son drained the trans oil and refilled it with Syn motor oil. And yes put it a quart over full. No problems. He also put a boost gauge from a Gleaner combine. Don't pull it above 20 lb. in fifth. In fact I try to keep the boost under 5 psi so I get over 20 mpg. Vic
 
(quoted from post at 23:51:03 03/04/14)
Correct, you need the adapter plate and starter from a 2nd gen. Not a big deal.
The 6 speeds do have issues towing in 6th gear. NV4500 does not have a problem towing in 4th at all. 5th in a 6 speed and 4th in a 5 speed are both direct drive.
REAL medium duty transmissions such as a RTO 6610 would handle towing heavy in overdrive every day of the week. But any trans that comes in a pickup truck cannot. Sure, NV4500 may have the weakest overdrive, but the others are not much stronger.

you can tow heavy so long as you dont have to apply more than stock power levels to overdrive. For example, if I have to apply more than 20psi of boost for more than 15 seconds, I downshift to 4th.

so my o5 dodge should have come unglueded pulling a 26 ft rv over east side of eisenhower with the tranny in 6th and the cruze set on 78?

unglueded?
Nope, not saying that at all. You can tow in overdrive, but if you apply more than stock power to overdrive in any pickup truck trans your not doing it justice.
 

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