3:73 not good for Diesels?

[pipaguapique]

Hey everyone!

I've been wanting to upgrade my 4:11's to 3:73's to improve my highway drivability, but the person who was selling me the new gears told me that it doesn't work as good on Diesels than it does on the 2F engines. Has anyone have any experiences with that?

Thx!

Jerry

 

[Gimme a 60]

BJ60s in Canada came with 3.73. They cruise nicely with stock tires.

If you’re running oversized tires, consider 4:10s.

 

[rick_d]

huge pet peeve
60/70 series got either a 3.70:1 diff or a 4.11:1 diff.
after 1990 things change up with small pinion fronts.

There are 4.10:1 and 3.73:1 that exist but not delivered for 1981-1990 HD land cruisers.

I use 3.909:1 vdj79 gears in my truck w hdt which for highway with 255/85/R16's (a 33" basically) and keeps highway speeds under 2700 rpm in what I have found in two decades of driving hdts sweet spot.

 

[bj70bc]

turbo diesel and 3.73 works good, otherwise i was going to regear

 

[VADUS]

Has anyone have any experiences with that?

I have been driving my TLC80 with stock 41;11=3.73 FGR for 20 years. I can admit, that with 33" tires it is probably the best ratio. However, I have pretty powerful 1HD-FT. For 35-36" tires you will probably need something around 4.1, like 41:10 or 37:9. If you have a weak engine and high weight, then 3.7 might be to heavy for your engine on a highway.

 

[pipaguapique]

Thanks guys. Mine's a 40 running 31's.
I'm going to try to borrow some 33's first to see if it'd be worth the gear change.

 

[David*BJ70]

Please help us help you. Without knowing your engine, we’re only speculating.

If it’s a 3B, I’ve personally owned a BJ70 (3.70 gear ratio) and a BJ60 (3.70 gear ratio). Even though there’s only an inch of difference, I found that the 265/75R16 wasn’t as effective as a 31×10.5R15 tire especially when I was climbing long highway grades.

I have a BJ42 with a 4.11 gear ratio. I’m running 31s, but I’ve also driven with 255/85R16 and 7.50R16 tires without any issues or even feeling a loss of power like I experienced with my BJ70 and BJ60. The 40 Series just isn’t a highway beast, so I don’t feel the need to change my gear ratio from 4.11 to 3.70.

 

[pipaguapique]

Please help us help you. Without knowing your engine, we’re only speculating.

If it’s a 3B, I’ve personally owned a BJ70 (3.70 gear ratio) and a BJ60 (3.70 gear ratio). Even though there’s only an inch of difference, I found that the 265/75R16 wasn’t as effective as a 31×10.5R15 tire especially when I was climbing long highway grades.

I have a BJ42 with a 4.11 gear ratio. I’m running 31s, but I’ve also driven with 255/85R16 and 7.50R16 tires without any issues or even feeling a loss of power like I experienced with my BJ70 and BJ60. The 40 Series just isn’t a highway beast, so I don’t feel the need to change my gear ratio from 4.11 to 3.70.

Hi David,

Of course! I have an FJ40 with an original B engine. Not a 2B or a 3B, just a plain ol "B". I've been recommended not to turbo it and just recently not to change the gear ratio because it would get even more sluggish. I know the 40 is not a highway machine, I'm just trying to optimize my ride as much as possible since right now, i can only seem to be able to go 50mph on a good day. Maybe that's all I can get with this engine?

Jerry

 

[David*BJ70]

A 40 with a B engine, son you own a BJ40

 

[pipaguapique]

A 40 with a B engine, son you own a BJ40

there was a little tear of joy when i read this.

 

[bj70bc]

A 40 with a B engine, son you own a BJ40

you said BJ

 

[David*BJ70]

you said BJ

Please clarify your comment. I’m not sure I understand.

Above he says he has an FJ40 with a B engine.

 

[bj70bc]

Uh huh huh huh huhu
You said BJ, huh huh

 

[David*BJ70]

@bj70bc : Je tentais simplement de comprendre dans quel esprit ton commentaire avait été formulé : sarcasme, humour, aspect technique, dénonciation ou approbation. Apparemment, cela restera un mystère! Parfois, la langue utilisée ne permet pas de saisir certaines nuances, aussi simples soient‑elles. Et comme tu le vois, l’anglais est une langue seconde pour moi.

 

[bj70bc]

@bj70bc : Je tentais simplement de comprendre dans quel esprit ton commentaire avait été formulé : sarcasme, humour, aspect technique, dénonciation ou approbation. Apparemment, cela restera un mystère! Parfois, la langue utilisée ne permet pas de saisir certaines nuances, aussi simples soient‑elles. Et comme tu le vois, l’anglais est une langue seconde pour moi.

just dumb humor, no worries

 

[Greek Cruiserhead]

HJ60/2H engine came with 3.73 in Europe during their 10 year-long career. They cruise nicely with stock tires.