Tranny specs for upgrade options

[whitetoy]

I have the original carbed 22R in my runner, and the G52 is
starting to show signs of wear (synchros in 3rd and reverse ).
Rather than simply have Marlin re-build it, I was thinking of
upgrading to either a R151F or G54 .

Questions about the G54 :
  1 -  lower 1st gear than the G52 ?
  2 -  can I use the same 21-spline TC  ?
               (contains Marlin gearset #67 and a twin-stick)
  3 - same overall length as a G52 ?
  4 - forward-shifting like the G52 ?
  5 - how can you tell a G54 from a G52 by looking at it ?

Questions about the R151F :
  1 - same overall length as the G52 ?

I know I'll have to replace the output (?) shaft of the TC with
a 23-spline, if I go with a R151F.

Thanx for your help.

[Marlin]

Whitetoy, thanks for your questions.
The G52 and the G54 share the same gear ratios, length, and t-case requirements
The only sure way to identifly the stronger G54 is to remove the nosecone and inspect the larger input bearing. If it is a sealed bearing, it is a 80x23 mm heavy duty G54 trans. However, early G54 still used the junk G52 steel 1/2 fork with nylon shoes that always wear out, and steel 3/4 forks. All G52's used the same front input bearing as the 83' L52. It is a 80x20 mm open face bearing and has a poor service record.  G54's also had upgraded aluminun alloy 1/2, 3/4, forks and a steeper, (stronger) helix angle on the input and countershaft constant run gears. Both G52 and G54's use the same stronger, narrow teeth rev idler gears.
This is my short answer

Because both G52-54 transmissions and R151F's  were designed for a bench seat truck, upgrading to the turbo trans is a 100% bolt in job providing you install a 23 spline t-case input gear. Both trans are 25.5" long and even use the same forward style t-case shift rods.

Remember that a G series trans uses 8 bolts in the center, W's use 9 and R's use 10 bolts to hold the transmission housings togeather.

Marlin

[whitetoy]

Hey Marlin, thanx for taking the time for a nicely detailed reply.
I know that the R151F is the best way to go, but they are hard to find, and pricier.
I was hoping that the G54 would have the lower first gear, like the R151F.
There are likely more G54's out there, and would be a true 'bolt-on'.

When my G52 finally dies, I'll be coming down to Fresno for one of your R151F's.