H55F gearbox 5th gear change info needed.

[cicak]

I am looking at how to reduce my revs in 5th only I am sitting on 2900rpm at 120k in 5th it's effortless for it so I want to try and reduce 400rpm which I think gives me 2100rpm at 100kph and 2500rpm at 120k. PS at 100kph I get 9-9.5k a liter or 23mpg out of it will all the Mods done its pretty good.

I am up for new syncro's in REDs H55F gearbox soon and I do not want to change diff ratios (9/41 or 4.56) I am happy with these offroad.

I know an engineering shop in Melbourne who used to recut gears

But I know no one here yet. Has anyone played with H55F gear ratios at all or can offer any advice.

5th if I can I want to reduce to 0.790 gives me 102k at 2000rpm

• type: 5 speed manual
• code: H55F
• gear ratios (to 1):
  • 1st: 4.843
  • 2nd: 2.619
  • 3rd: 1.516
  • 4th: 1.000
  • 5th: 0.845
  • rev: 4.843

• code: H55F
• low gear ratio: 1.959:1

 

[ForealBoreal]

I am also really interested in this sort of thing.
If anyone posts it the safari gear is for the h151 not the h55

 

[Hulsty]

Transfer case gears, get a overdrive high range, or with all factory stuff you can have 2.3 ratio low range and 4.11 diffs which will give you what you want and maintain the same low range ratio more or less. This is what I have, sits on about 2200 I think at 100km/h, which is about max torque.

 

[1998hzj75]

Safari makes a kit for the h55f for such reasons as a turboed 1hz has the balls behind it but the revs are too high. If you go down this path I would replace the shaft, no personal experience but blokes at work have had a snapped one (supposedly can't handle the different gear, not too sure, look into it more)

 

[ForealBoreal]

I have contacted safari looking for this gear in the past. It does not exist. I would love to get ahold of something like this.
Can you find out more info?
There is only one suited to the h151

 

[Radd Cruisers]

Safari makes a kit for the h55f for such reasons as a turboed 1hz has the balls behind it but the revs are too high. If you go down this path I would replace the shaft, no personal experience but blokes at work have had a snapped one (supposedly can't handle the different gear, not too sure, look into it more)

The Safari gears are not for the H55F, they are for a later model 70 Series transmission - one of the aluminum jobs.

My HZJ77 needs much taller gears, highway driving long distances with 4.10s and the H55F is very tiresome and slow, plus the fuel economy takes a hit as well.

~John

 

[cicak]

Transfer case gears, get a overdrive high range, or with all factory stuff you can have 2.3 ratio low range and 4.11 diffs which will give you what you want and maintain the same low range ratio more or less. This is what I have, sits on about 2200 I think at 100km/h, which is about max torque.

THanks for this sounds perfect but the issue I forgot to put in is the GOD winch. It runs off HIGH ratio xfer case and pulls on a 4:56:1 prado diff also so I cannot go up much in the xfer case hence 5th gear change only as all the other gears are fine for my driving here only 5th needs to be changed with the 35" sneakers.

 

[Gengis]

Marks do an 8% overdrive ( Transfer case , so it affects all gears)
http://www.marks4wd.com/overdrive-gears/toyota/mfk1194tr.html

Farking expensive if you don'e live and earn in aussie.