Regearing to 4.88s

[I Lean]

I'll revise my earlier reply about 33's possibly being too small to work well with 4.88's. I finally took a good long road trip in mine (on 35's), and with the cruise set at 80 MPH, running close to 3000 RPM's, I netted 15.5 MPG between SLC and Las Vegas, and 14.8 on the return leg, Vegas -> SLC. The higher RPM's are what I was initially worried about, but it didn't seem to care AT ALL. So for towing especially, the deeper gears will be grand.

 

[RiverRatMatt]

I ordered a set of underdrive gears for the high range from cruiser outfitters today, though they're backordered. Does anyone have any install instructions or a video they could link me to?

 

[bozncsurf]

I ordered a set of underdrive gears for the high range from cruiser outfitters today, though they're backordered. Does anyone have any install instructions or a video they could link me to?

PLEASE document your experience with these! Would love to get a little pep back without losing my highway rpm’s

 

[Skidoo]

I ordered a set of underdrive gears for the high range from cruiser outfitters today, though they're backordered. Does anyone have any install instructions or a video they could link me to?

Marlin Crawler has a great guide for installing their crawler gear in the low range. The high range is kind of the same steps.
I did the crawler gear install on mine and I recommend pulling the t-case if you can. Their instruction did without pulling the t-case.
Our new 80 & 100-series Land Cruiser Low Range Gear Kit Install
I don't think you have to grind the case like low range install, but don't know for sure.
For this level of work you should have a FSM for your year Cruiser, might get by with another year, or you might find a surprise.
Found some surprises trying to do the crawler gear install in a friend's 80 without the same year FSM.

 

[ClassyJalopy]

I am so interested in the high range install too - but I have zero experience in setting gears, lash etc. Does anyone know if this needs any special tools or is it possible do on your back in your driveway?

 

[Skidoo]

I am so interested in the high range install too - but I have zero experience in setting gears, lash etc. Does anyone know if this needs any special tools or is it possible do on your back in your driveway?

There is no setting gears, lash, just press off, press on. Regular tools and of course a BFH and some fancy language may be required.
Once you get the gear stacks out you need a press get the old gears out and new ones in.
Or you could take the stacks to a shop for the press work.
I replaced bearings so needed to set bearing preload which required a micrometer and some shims.
This guy has two videos on replacing both low and high range gear sets on an 80 but pretty much the same t-case.

 

[RaRasMulita]

anyone in california you can recommend that can do this job?

 

[trdcorolla]

RPM Garage in Monrovia

 

[Skidoo]

Valley Hybrids, in Stockton, probably the best t-case shop in the country.

 

[MongooseGA]

What's the recommendation for a 5-speed running 34" tires? Are 4.88s going to have me buzzing like crazy and topped out at 70 MPH?

 

[Skidoo]

I have the 4 speed with 4:88 and 295s. Stock the effective ratio in 4th gear is 3:24 and with 4:88 its 3:67. With the 295s and stock gears speedo read 5% slower, after it reads 5% faster than actual speed. Stock for the 5 speed the effective ratio in 5th gear is 2:94 and with 4:88 its 3:49.
Offroad the 5 speed is more tolerant of larger tires as its 1st and 2nd gears are lower than 4 speed.
If you load the Cruiser heavy and do a lot of mountain driving at highway speeds those 4:88's will make the hill climbs a lot easier.
Certainly will not be topped out at 70, should be able to go over a 100. A 100 does NOT buzz, even at 100, not in its nature.
My 4th gear is lower than a 5 speeds would be and I don't feel I have given anything up at highway speeds.
If you are debating getting lockers and thinking gears at same time, locker with stock gears should work pretty well. 4:30 gears are interesting for 5sp as the speedo would probably be right for 34 tires.
Another path is to go with a crawler gear in T-case, (no lockers) with my crawler gear I don't have to use my lockers very much anymore.

 

[MongooseGA]

I wish I could say I were a smarter man and could wrap my head around all of the info here without having to go watch some youtube videos..

Essentially you're saying, 4.88s would not turn my truck into a trailer queen that can't run comfortably on the highway.

 

[ClassyJalopy]

@Skidoo is saying that 4.30 gears from 2002 and earlier ones will probably be ideal for your set up of 34" wheels. Which means you could get inexpensive front and rear (even a a locked rear) from another truck and use your money an actual front locker!

I wish I could say I were a smarter man and could wrap my head around all of the info here without having to go watch some youtube videos..

Essentially you're saying, 4.88s would not turn my truck into a trailer queen that can't run comfortably on the highway.

 

[MongooseGA]

@Skidoo is saying that 4.30 gears from 2002 and earlier ones will probably be ideal for your set up of 34" wheels. Which means you could get inexpensive front and rear (even a a locked rear) from another truck and use your money an actual front locker!

These were the magic words that unlocked my understanding

 

[ClassyJalopy]

These were the magic words that unlocked my understanding

Look up Benzeen auto - they shipped me a pristine, rust free (seriously even the parking brake components we fine!) full rear axle with factory locking diff for $500 including shipping! Low range offroad has a plug and play harness to make it all virtually pain free!

 

[Skidoo]

I wish I could say I were a smarter man and could wrap my head around all of the info here without having to go watch some youtube videos..

Essentially you're saying, 4.88s would not turn my truck into a trailer queen that can't run comfortably on the highway.

I live out west, have heavily modded rig, load it heavy and do lots of mountain driving and therefore like the 4:88 both on hway and offroad.
And it is very comfortable doing 85 for hours on Utah interstates.

Had stock gear in the LC for the first 8 years of offroading, just past couple its had 4:88s.

What is your goal? What has you thinking about 4:88s?

 

[Skidoo]

Look up Benzeen auto - they shipped me a pristine, rust free (seriously even the parking brake components we fine!) full rear axle with factory locking diff for $500 including shipping! Low range offroad has a plug and play harness to make it all virtually pain free!

The brake line plumbing is different on 98-99 rear axles as common line to both brakes. 2000 and later have separate lines to each brake. So need to swap lines over.

 

[MongooseGA]

I live out west, have heavily modded rig, load it heavy and do lots of mountain driving and therefore like the 4:88 both on hway and offroad.
And it is very comfortable doing 85 for hours on Utah interstates.

Had stock gear in the LC for the first 8 years of offroading, just past couple its had 4:88s.

What is your goal? What has you thinking about 4:88s?

I'm in an odd position where it's possible I may need to replace something in the diff. Figured it might be worth it to look into this if that's going to be the case.

Ultimately, I'd like to have some semblance of passing power and not hear my truck wailing in 4th or even 3rd gear to get up a mild to moderate grade at 75mph. Around town pep isn't that important to me for this vehicle, but the throttle on the highway is really just an engine-noise-amplifier right now.

 

[ClassyJalopy]

The brake line plumbing is different on 98-99 rear axles as common line to both brakes. 2000 and later have separate lines to each brake. So need to swap lines over.

The plumbing from his current rear axle will easily transfer on the replacement axle!

 

[Skidoo]

I'm in an odd position where it's possible I may need to replace something in the diff. Figured it might be worth it to look into this if that's going to be the case.

Ultimately, I'd like to have some semblance of passing power and not hear my truck wailing in 4th or even 3rd gear to get up a mild to moderate grade at 75mph. Around town pep isn't that important to me for this vehicle, but the throttle on the highway is really just an engine-noise-amplifier right now.

If you have to crack open the diffs then 4:88 will help. If you don't have to mess with the diff, then could get 10% lower gears by changing the high range gear in the t-case. The underdrive gear set here for 80/100s. Might be the cheapest option.
Toyota Land Cruiser T-Case Gear Sets