First question is what are my gear ratio's? I checked the FAQ section and couldn't find a link to a "spec's" area. I also did several searches and got nada.

I've gathered from various posts that the Getrag 238 in my truck is OK, but far from the strongest tranny out there. The G56 would be indestructible in a half ton, but is not a plausible swap due to the engine computer not knowing it's there (let alone what it's doing.) So who's had a Getrag 238 die, and what happened? Was it gears, synchro's bearings what? and did you just have it rebuilt? Are there stronger gears or other parts available? Can it be replaced with a different unit? (A Tremec for example?)

I'm one of those folks who hates automatics and I was very glad to find my truck with the standard and the options package it has. Unless something completely unforeseeable happens I plan to keep this one for a long time.

 

Glove compartment may have a sticker indicating your gear ratio.
It may also be somewhere on the axle.

 

I killed mine 2 years ago. The dealer said that I bent both rails and shattered 3rd gear. It was rebuilt under warranty, so I really don't know what exactly happened as I did not get the parts back. I am not exactly sure what caused it other than I use my truck like a real truck. I coasted into the driveway in 3rd gear and shut it off while coasting. The next morning when I went to start it, I started it, shook the stick to make sure it was out of gear, and set the brake. It stalled out. truck was locked in gear. I would also be interested to know if anything else bolts to the 4.7 other than an auto. For example: Does the 5 speed fit from a 2004 4.7, and is it any more durable? I have made a few inquiries, but with no luck. A used 238 can be had on fleabay for about $800.00.

 

Kay9, I dont think he wants rear diff gear ratio but trans gear ratios.

GEAR SPECIFICATIONS
GEAR RATIO
FIRST 4.23
SECOND 2.53
THIRD 1.67
FOURTH 1.23
FIFTH 1.00
SIXTH 0.79
REVERSE 3.84

 

I know what final drive ratio I have. I just wish it was different!
Maybe the Christmas Fairy will drop $1500 in my stocking and a set of 410's with a Detroit True Track rear will arrive thereafter.

BTW, I only do light off road, but a decent amount of snow.
Which is better for snow the DTT or the conventional (Auburn) type LSD?

 

The 238 is a rated for about 380 FT LB. The ratios above are correct.

The NV 3500 (the 5 speed from older 1/2 ton trucks) is rated around 300 FT LB. They are also notoriously difficult to rebuild, and require special fluid. The bellhousing may be compatible, but the two transmissions are likely different lengths.

I think the 4.7L engines came with slightly larger clutches than the 3.7L.

Overall they seem to be pretty tough units. They are rated for more input torque than any other 'modern' (5+ speeds, non-granny 1st gear, fully synchronized) light truck gearbox. The next step up is a tough, slow shifting NV4500, 5600 or Mercedes G56, or a sporty but tow/haul unfriendly Tremec.

 

Sorry for the bad info there.

 

g238 is fine. Compare how many of these you see that are toasted to 545rfe autos that die.....

 

Thanks for the info everyone. I didn't think about e-bay and the fact that a lot of the 6 cylinder trucks have the 238 too. I do minimal off road, or towing. And I've been driving a manual for over 30 years, so I'm not unnecessarily hard on it.

My last truck was a 72 F-100 with a 390 and a 10 bolt top loader. (SB 4X4). In that setup the trans was damn near indestructible.

I guess I'll just have to keep suffering through owning a truck with no rust holes in it, power windows instead of cranks, AC, power brakes, no trips out into the snow to lock the hubs, and the capacity to pass a gas station now and again.. (I do miss the torque tho...)

 

so how did you find out what the gear ratios were? Because I looked in my owners manual and I couldn’t find where it told me the gear ratios?