Split-Case re-gearing, rebuilding and machine work (1 Viewer)

[cruiserpilot]

I think the Mark’s gears are 8% overdrive

The Sumo gears are 10% …… and you won’t need to wear ear muffs when driving your cruiser, which you would have to do with the Marks gears.

The end.

Does anyone have a video of what these Marks gears sound like? I'm very curious now.

Videos never convey sound properly……

I‘m gonna yell!! MARKS gears are awful!! I had a set for over 5 yrs. 87 dB, always. Beyond Awful!!
Do not be curious, do not think about it, stay away!!!
I just returned from my first road trip with SUMO GEARS, it was like driving in a vacuum
by comparison. I could even listen to my stereo.
Listen to Georg, because if you get Marks gears you won’t be able to hear him over the whine!
Do y’all understand? J
Call me if you want my honest opinion

 

[lowtideride]

Just wondering… is there an option to run the 10% overdrive gear with the 4:1 set of gears?

 

[orangefj45]

Just wondering… is there an option to run the 10% overdrive gear with the 4:1 set of gears?

No sir. The 4:1 gear set comes with all 4 Tcase gears …… no options other than a 10% UD in high range.
But we can supply a 10% OD high range set with a 3:1 reduction in low range.

Georg @ Valley Hybrids @ Cruiser Brothers

 

[lowtideride]

No sir. The 4:1 gear set comes with all 4 Tcase gears …… no options other than a 10% UD in high range.
But we can supply a 10% OD high range set with a 3:1 reduction in low range.

Georg @ Valley Hybrids @ Cruiser Brothers

Thanks for the response. I also need to buy your rear drum split-case adapter setup thing. Looks like 3:1 and the overdrive gear are the way to go.

 

[orangefj45]

Thanks for the response. I also need to buy your rear drum split-case adapter setup thing. Looks like 3:1 and the overdrive gear are the way to go.

Happy to help. Feel free to call or email us when you’re ready bud!
Georg @ Valley Hybrids @ Cruiser Brothers
Shop 209-475-8808
Sales@valleyhybrids.com

 

[JKIII FJ40]

Way too many options!
So, by regearing the TC with the 10% OD I have to ask if it's necessary to install a H55? The gear ration calculator is awesome, but I wasn't able to figure out how to add the 10% over drive as a factor. I have a good H42 out of a 60 and just tore down the TC (gen1 34mm) to see the condition inside. I'm running 4.11's in my 40 and like the short 42 and really didn't want to squeeze a 5 spd in. My motor is strong, and I just don't want to run it above 3k for long. I know its fine and I am probably more cautious than I need to be.
Basically, weighing options George. It seems the more I research I find I have more questions than answers on what I am going to do.

 

[cruisermatt]

Way too many options!
So, by regearing the TC with the 10% OD I have to ask if it's necessary to install a H55? The gear ration calculator is awesome, but I wasn't able to figure out how to add the 10% over drive as a factor. I have a good H42 out of a 60 and just tore down the TC (gen1 34mm) to see the condition inside. I'm running 4.11's in my 40 and like the short 42 and really didn't want to squeeze a 5 spd in. My motor is strong, and I just don't want to run it above 3k for long. I know its fine and I am probably more cautious than I need to be.
Basically, weighing options George. It seems the more I research I find I have more questions than answers on what I am going to do.

think of it making your axle ratio 3.73's when in high range. Yes you can absolutely install aftermarket t-case gears behind a H42. The t-case doesn't know what transmission is in front of it. However there isn't a set of 10% OD gears available as a drop-in for 34mm cases to my knowledge. Someone please correct me if I am wrong on that.
But you should have no problem getting a 86-up 38mm idler gear and low speed gear and the stepped 34/38mm idler pin. Obviously if you can find a complete 38mm core for under $500 go with that.

Is your case a 80-82 or 83-84?
Just had a customer with a 81 splitcase we did (80-82 cases have a unique input seal/spacer setup) and I'm not sure you could even put aftermarket gears in those as the seal is in a physically different spot compared to +10/82 versions. Again someone please correct me if I am wrong but I don't see how that would work..

 

[JKIII FJ40]

many thanks for the info. basically I would be geared like a 60 (granted i could find the case and such). good to know there are options.

 

[blByrd1]

Has any body installed the 4:1 gears into a fj62 with the iron pig 4.0?

 

[orangefj45]

Has any body installed the 4:1 gears into a fj62 with the iron pig 4.0?

We’ve done a few.

Very important!!!!
You have to run the Tcase output shaft from a mechanically shifter split case or IT WILL POP OUT OF GEAR.
We can help with all the parts for this project AND proper tech support.

Georg @ Valley Hybrids @ Cruiser Brothers
Shop 209-475-8808
Sales@valleyhybrids.com

 

[blByrd1]

Did Sumo ever make the input gear full with full length splines?

 

[JakeisbadatThis]

We’ve done a few.


Georg @ Valley Hybrids @ Cruiser Brothers
Shop 209-475-8808
Sales@valleyhybrids.com

I'm trying to decide between the 3:1 and the 4:1 gears. For the machining, have you seen cases running the 4:1 break? A couple of the older guys in my cruiser group said they felt it took out too much material, but i'm not able to find references online of cases cracking or breaking. I really like the 4:1, but i am worried i'm gonna crack the case with a little too much 3B power lol

 

[orangefj45]

I'm trying to decide between the 3:1 and the 4:1 gears. For the machining, have you seen cases running the 4:1 break? A couple of the older guys in my cruiser group said they felt it took out too much material, but i'm not able to find references online of cases cracking or breaking. I really like the 4:1, but i am worried i'm gonna crack the case with a little too much 3B power lol

I’m not sure who the “older guys in your club” are …… but the first thing I’d ask would be “Have you ever seen one break?” And I mean first person, not “my cousin Billy-Bob’s neighbors uncles step-sisters baby-daddy said ….”

I’ve never seen it. And I’ve seen well over 100 machined cases that I’ve built. I’ll leave it at that.

Georg @ Valley Hybrids @ Cruiser Brothers

 

[Beerfix]

Going on 3+ years now since Georg cut my cases, supplied the 4:1 gears, and I assembled it. I haven't been all that nice to it, and I managed to grenade a AA Ranger overdrive, and a rear Toyota U-joint in the mean time behind a somewhat built GM small block/H42. The machined case and gears are surely not the weak point. I'm glad I went 4:1, and I'd do it again. I got a tiny bit of metal debris on the breakin oil change, but not a speck since then. Probably the most meaningful and useful upgrade I've done. Not too worried about the 3rds since with the underdrive of the 4:1 set, and the overdrive of the ranger, I was able to retain my 3.7s with the massive pinion. Axles and U-joints are still the weak link.

 

[JakeisbadatThis]

I’ve never seen it. And I’ve seen well over 100 machined cases that I’ve built. I’ll leave it at that.

Georg @ Valley Hybrids @ Cruiser Brothers

The machined case and gears are surely not the weak point.

Thanks for the info! that puts my mind at ease, i'm not to the point where i'm ready to order yet, but when i pull the transmission to replace the clutch i'm gonna reach out for a set of 4:1 with the 10% underdrive!