3.73 to 3.42 gear conversion results request

[AH64ID]

I think that would really hurt towing performance... .

 

[BHolm]

I don't think I would go that far myself either but, if you could go to a . 72 from the . 79 ending up a little taller than the . 74 of the late ratio G56 I suspect I would really be happy with that.

 

[DLane]

Has anyone checked in to replacing the overdrive gear only in the nv5600 or g56 with say a 0. 625 overdrive gear. I dont have a clue but I can only assume this would be cheaper. Yes the trans would have to come out to replace the overdrive gear if there is a gear made that would fit our trans.

You would most likely find the "jump" from 5th to OD to be to big. The 5spd trucks 1st always seemed about right for towing, Just needed one more gear on top. When the 6spds came out they just put the additional gear on the wrong end of the shift pattern. I think the way to figure this would be to take the ratio of 1st gear in the NV4500 w/3. 55s against the ratio of 1st in the G56 to find a axle ratio that will allow the best use of this transmission as is or even better with a swapped in new . 74 OD.

Anyone know the 1st gear ratio in the NV4500 and the G56?

 

[DLane]

Well I should have searched that info before I posted above.

Going by the 1st gear comparision I come up with 3. 16 axle ratio. Going from a 2nd gear comparision I come up with the same 3. 10 axle ratio as I did with the . 79 G56 OD compared to the . 69 OD in a second gen auto w/3. 55s.

With 3. 08s 2000rpms would give you 77/61 mph in OD and 5th respectively.

SOOOO anyone know if 3. 08 or even up to mid 3. 20s are even available? I want NOOOO NEED them

 

[PGarrett]

Again has anyone ckecked for a taller overdrive gear that would fit the nv5600 or g56?

 

[AH64ID]

NV 4500

5. 61

3. 04

1. 67

1. 00

0. 75



NV 5600

5. 63

3. 38

2. 04

1. 39

1. 00

0. 73



G56

6. 29

3. 48

2. 10

1. 38

1. 00

0. 79/0. 74





The extra gear is between 1 and 4. 1 and OD are the same, direct is still right before OD... so the difference is there are 3 gears between L and Direct, vs 2 gears. So its better for getting a load moving and for pulling mountain roads.



The 2nd OD is only really needed when cruising empty, which is why I dont think 3. 42's are the best option. . where the GV does both... extra gears for cruising hills and towing, and a better OD when empty.

 

[SShafranko]

I got a price in NJ by a very good shop who only do gears for$1,550. 00 including parts.

 

[KBalzuweit]

I still say gears. The gear Vendor with its need for oil changes every 5k is too high maintenance to me. Heck before I spent 4k on a GV I would look into an allison swap!

 

[jcarey]

I got a price in NJ by a very good shop who only do gears for$1,550. 00 including parts.



That sound very reasonable. What the name of the shop and where in NJ, please?



Thanks