3:70 gears in an 80 series?

[Workhorse]

Has anyone swapped out their 4:10 for 3:70 differential gears in their 80 series? I have an H150F manual 5 speed and I run out of (comfortable) top end at about 65 or so. At least that is where my HDFT seems to be happy cruising, right at about 2400 RPM's. I do have a lift with 315/75R16's (35's) which help, but was looking for more overdrive than that.

I was wondering if anyone here had an 80 series with manual 5 speed has done the swap to 3:70 diff gearing. If someone from a European country with a manual transmission 80 series might chime in with any insight?

Thanks in advance for any information.

Ross-

 

[jonnyquest]

Hey Workhorse. I don't know enough about the 80 series to answer your question. But your Cruiser sounds real interesting. Can you talk about it a bit? Did you import it? Does it have the AWD?

 

[temple]

Your question is confusing since I don't know that anyone will understand your experience: 4.10, 35's, top speed around 65.

I have 4.45, 35's, cruises at 80 mph all day long.

 

[1911]

Has anyone swapped out their 4:10 for 3:70 differential gears in their 80 series? I have an H150F manual 5 speed and I run out of (comfortable) top end at about 65 or so. At least that is where my HDFT seems to be happy cruising, right at about 2400 RPM's.

No surprise there, since the 1HD-FT generates its peak torque at 2500 rpm.

35's and 3.70 gears + the weight of an 80 might be a tall order to pull, but on the other hand the 2F in my 40 (with 100 ft. lbs. less torque) pulls my 3.70 diffs and 33" tires easily and is a good combo.

 

[Workhorse]

Johnnyquest, not imported. I bought the truck from the original owner in 2003 with 60,320 miles on it. I (with the help of a good friend) converted it over to a Factory Toyota turbo diesel with manual H150F transmission (Yes it is AWD) using only Toyota Factory parts, harnesses, interior trim and related. It turned out well. I will have to post a photo or two sometime.

Temple, my guess is that you have an automatic transmission which has a taller final drive ratio, hence the 80 MPH all day long. I have never heard of an 80 series with 4:45 gearing so my guess is that you have a 100 series with an automatic?

1911, I don't believe that the 3:70 gearing will change anything too drastically, maybe lower the top end cruising RPM's by 200-300 which would be a nice change. It drives very nicely as-is, just wondering if there is anyone else out there pondering the same thing.

Maybe one of our European friends might chime in with some information.

Thanks for the interest gentlemen.

Ross-

 

[temple]

I meant 4.88's. She's definitely an 80 series.

 

[Pokey]

Has anyone swapped out their 4:10 for 3:70 differential gears in their 80 series? I have an H150F manual 5 speed and I run out of (comfortable) top end at about 65 or so. At least that is where my HDFT seems to be happy cruising, right at about 2400 RPM's. I do have a lift with 315/75R16's (35's) which help, but was looking for more overdrive than that.

I was wondering if anyone here had an 80 series with manual 5 speed has done the swap to 3:70 diff gearing. If someone from a European country with a manual transmission 80 series might chime in with any insight?

Thanks in advance for any information.

Ross-

If you are stock weight or close (ie not a ton of bolt ons) you should be good with 3.73s. Hdft pushes a bit more torque than 1fz off idle so you won't notice it around town and your turbo will likely pull hills unless too steep or you are carry lots of extra weight. As always it's a trade off with hwy vs off-road......so if youre onroad outweighs off-road time- go for it.

 

[Workhorse]

Thanks for the information and insight Pokey. Do you have an 80 with 3:70's?

I have the HDFT with the H150F, not the H151F 5 speed transmission, which has a lower first gear than the H151. It gets up and moves very well. Most of my driving is highway and around town, with some back country offroad time. Do you have any first hand experience with the set up I am asking about?

 

[lt1fire]

does anyone even make 3.70 gears for the 80??? never seen them advertised before. I do remember hearing that some Euro cruisers did come with them but they are very rare and toyota no longer makes gears for them.

If someone has a line on them i'd be interested after my diesel conversion

 

[1911]

does anyone even make 3.70 gears for the 80??? never seen them advertised before. I do remember hearing that some Euro cruisers did come with them but they are very rare and toyota no longer makes gears for them.

If someone has a line on them i'd be interested after my diesel conversion

40 and 60-series 3rd members will drop right in the rear diff of the 80, and late 60 and all 62 flanges will bolt-up. The problem is the front diff on the 80, which uses a reverse-cut 8" ring gear. Toyota did make 3.70 gears in JDM model 80's though.

 

[Workhorse]

Toyota still makes the 3:70 gears specifically for the 80, both front and rear. The European manual transmissioned 80's got them. JDM spec 80's never had them nor did the OZ or SA models, European markets only.

I'm not sure of any aftermarket gears available. Toyota gears are spendy, but very high quality. Maybe I will be the first to do the gear swap and can report to all here of the results.

Thanks for the interest gentlemen.

Ross-

 

[60Dan]

I asked this same question on Mud last year.

Here is the link, may have some interesting info for you:

http://forum.ih8mud.com/threads/how-to-id-3-73-gears.605070/

 

[Workhorse]

I believe we have spoken on that thread before, you are UK Aviator, yea?

I am contemplating pulling the trigger with Akella here in the next month or so. I will post up differences, benefits and possible losses with the change. If I go that route, I will purchase the front diff assembly complete and the rear gears, both Factory Toyota, not aftermarket. I will keep you posted.

Ross-

 

[60Dan]

Yeah thats me. Looking forward to hearing your thoughts.
Will be checking this thread frequently

 

[hoser]

Probably not what you would choose but an interesting option, nonetheless. T-case gears HI: 1.097 and LO: 3.317

ZEAL transfer down 80,100 for high 10% low 33% down
(translated)
Land Cruiser 80, 100, for Cygnus. The down Haigia, in Rogia both. 10% down in the gear ratio Haigia 1.097, about 33% down in Rogia 3.317, needs to be modified in the case mounting. Input shaft 80 is required in another case to be attached to the Land Cruiser 100. 252,000 yen