1983 BJ60 Tcase 2WD Gear ratio

[yotahed]

I have put a 1983 3b H55F & split case in my 1991 prado. With 33's and 4.88's the revs on the highway are a bit high for my liking, and first gear is almost unessesary to start from a stop. What Im wondering is, is there a 2wd transfer case gear swap available to up the ratio to put the revs down 20% or so? I like the 4.88's for off roading in 4lo as it crawls quite nicely, but for highway use I see 100km/h at 2700 rpm, which I think is a tad high. I'd like to see 2300rpm at 100km/h without changing tire size or doing the diffs if at all possible. I also want to stay away from add on overdrives and the like. Let me know your thoughts.

cheers

jon

 

[roscoFJ73]

I think Marks Adapters make a set of t/case gears that will give you a higher high and a lower low

 

[Hulsty]

It may be difficult to only alter the high range gearing, the marks set as above alters both high and low range. Practically it may be easier to swap the diffs to 4.11 and change just the low range gear set which can be easily done. This is what I have done, low hwy rpm ~2200 100km/h and good performance in low range

 

[yotahed]

I have heard of the Mark's option, I heard they are quite noisy? cost? how are they for longevity? I also wasnt sure what was available for my diffs, as I have a High pinion 8" front and thought it was a goofy setup to get gears for. this is true?

thanks guys

 

[roscoFJ73]

I have heard of the Mark's option, I heard they are quite noisy? cost? how are they for longevity? I also wasnt sure what was available for my diffs, as I have a High pinion 8" front and thought it was a goofy setup to get gears for. this is true?

thanks guys

Ive never had them but the his newer types are supposed to be quieter.Longevity doesnt seem to be a problem.
Try asking the same question on the hardcore forum on MUD,probably get more opinions there

 

[Radd Cruisers]

The Mark's transfer gears are very strong, and they produce noise on par with that of a set of radial mud tires at highway speeds.

I have them in two of my LCs - an HJ61 and a BJ74 - love the ratio, but would go for lower if there was no primary reduction as in the Advance Adapter's gears which are 1.1:1 high and 4:1 low.

The best bet is going to be to get a set of gears from an 80 series for the front high pinion (4.10) and a pick-up (Hilux) gear set for the rears, also 4.10.

~John

 

[yotahed]

Thanks John

So the gearset from a 80 series high pinion front will fit my front?
What about the rear> generic toyota 8" diff gears?

I also think this would be the ticket for good highway use.
What about a 4.56? What kind of reduction would that give me. I dont want to go too high and have 5th gear unusable with the 33's, a drop of 500rpm would be perfect. I'd like my hwy rpms at 100kms at around 2300, as that seems to be the sweet torque spot of the 3B

Thoughts?

appreciate the input. Gears arent my strong suit.

 

[yotahed]

Just did the math, lol 4.10 looks perfecto. 16 percent drop. thanks John

 

[crushers]

or do as i did with the PZ/R151 swap ...
larger tires.
i went to a set of 35s and the RPM was very acceptable, the performance very acceptable and the looks ... well ... in my opinion, NICE.

IF you do decide to go this route then go with the Dobinson lift instead of the OME, better ride, better performance.
cheaper than a gear swap.

 

[yotahed]

Thanks Wayne,
I mulled the idea of 35's over 33's for a good month while tire shopping. Figure for a DD 33's would be the most acceptable, as my better half is 4'6" and almost needs a step to get in as is. lol
Im currently running pradocruzer's old 4 1/2 dobinsons with 2" spacers in the front to take up the the 3B weight difference. sits level all the way round +- 1/2"

Might try to find a good v6 third for the rear and a 80 series HP front with the 4.10's from a wrecker/craigslist/kijiji/mud. we'll see i guess.
For now It's fine, and Im getting almost the same mileage as my 2lte got give or take a tad.

 

[crushers]

interesting
i found with the PZ and 5 speed and turbo my fuel economy went up from low 20s with the 2LTE to just shy of 30 with the new set up at the same speeds and terrain.
i know of a 4.56 elec locker rear diff here that has under 20,000 km on it. it was a brand new toyota center unit.
i think you can get it for around $500.
cheers

 

[yotahed]

mileage

I was half expecting to get far lower economy with an old 3b, but the 2lte got about 10-11L/100km consistently( 650km out of a tank) and the 3b is right around the same, but thats with a leaking head gasket, dirty injectors, playing with fuel, etc.
and high revs probably dont help on the highway....

I might be interested in that locker...gotta get some coin together first.