Fenderfour
Member
I think so. It's an interesting idea, but my truck is at the shop getting new gears. I know a few folks that have these trucks and most are interested in regearing them. I'll pass the idea along.
1993 HiAce Firetruck Build Thread
- Thread starter Fenderfour
- Start date
Fenderfour
Member
New gears are installed. I also added a Detroit True Trac limited slip in the rear.
The truck can go 60mph at ~2800 RPM, which is great. The downside is the 2.4 liter NA diesel runs out of power going up hills, and requires a downshift to 4th gear. 4th gear feels just like 5th did pre-gear change.
Folks want to know about fuel mileage differences pre and post gearing. This is tough to estimate because of how diesel engines work. You can dump as much fuel as you want, and it will burn away into black smoke. So if you are a heavy-footed driver, there will be no difference. If you drive more carefully, there will be a difference. I haven’t been tracking fuel consumption, so I don’t have data.
In the city the truck feels so much better. Previously, driving 30-35 mph was odd, it required a lot of shifting between 3rd and 4th. Now the truck rides confidently in 3rd. Overall, the gearing just feels right, and driving is more intuitive.
I would recommend that anyone considering regearing one of these trucks research getting a junkyard rear 3rd member as AlloChris mentions above. The whole unit will bolt up to the driveline, and the axles will fit, since they all had 27 splines back then. It would save quite a bit of money. Either a V6 or 4 Cylinder toyota 8" housing will bolt right on. Some years of the 4Runner had a factory E-locker with the same housing. You could regear and add a locker for not much money.
I'm not sure what's next for the truck. I've been reading about adding a Ford E/F series tank in place of the spare tire to increase range, as the current tank is around 15 gallons. This seems like a really good option since a new E/F series tank is under $200, and any aftermarket aux fuel tank is $1500+. The tanks come in a range of sizes from about 17 gallons to 38 gallons.
I'm also considering working an Arduino project to get some compact gauges added to the truck. I currently have an Autometer diesel tach, will need to add an aux fuel level, exhaust gas temp, diff temp, transmission temp, etc... adding all of those analog gauges will take up a bunch of space. Using a small OLED or LCD screen will be neater.
And of course there is the camper itself. I need to make some new models for FEA and run some fatigue scenarios to see how it shakes out.
The truck can go 60mph at ~2800 RPM, which is great. The downside is the 2.4 liter NA diesel runs out of power going up hills, and requires a downshift to 4th gear. 4th gear feels just like 5th did pre-gear change.
Folks want to know about fuel mileage differences pre and post gearing. This is tough to estimate because of how diesel engines work. You can dump as much fuel as you want, and it will burn away into black smoke. So if you are a heavy-footed driver, there will be no difference. If you drive more carefully, there will be a difference. I haven’t been tracking fuel consumption, so I don’t have data.
In the city the truck feels so much better. Previously, driving 30-35 mph was odd, it required a lot of shifting between 3rd and 4th. Now the truck rides confidently in 3rd. Overall, the gearing just feels right, and driving is more intuitive.
I would recommend that anyone considering regearing one of these trucks research getting a junkyard rear 3rd member as AlloChris mentions above. The whole unit will bolt up to the driveline, and the axles will fit, since they all had 27 splines back then. It would save quite a bit of money. Either a V6 or 4 Cylinder toyota 8" housing will bolt right on. Some years of the 4Runner had a factory E-locker with the same housing. You could regear and add a locker for not much money.
I'm not sure what's next for the truck. I've been reading about adding a Ford E/F series tank in place of the spare tire to increase range, as the current tank is around 15 gallons. This seems like a really good option since a new E/F series tank is under $200, and any aftermarket aux fuel tank is $1500+. The tanks come in a range of sizes from about 17 gallons to 38 gallons.
I'm also considering working an Arduino project to get some compact gauges added to the truck. I currently have an Autometer diesel tach, will need to add an aux fuel level, exhaust gas temp, diff temp, transmission temp, etc... adding all of those analog gauges will take up a bunch of space. Using a small OLED or LCD screen will be neater.
And of course there is the camper itself. I need to make some new models for FEA and run some fatigue scenarios to see how it shakes out.
KiwiMtnClmbr
Member
Just get a second marine or rv tank and a transfer pump setup. No need to have an oem style fuel tank if you leave the stock one in place.
Fenderfour
Member
That's essentially what I'm doing, just getting an inexpensive ($170 new) E/F series tank to do it. They fit between the rails and have a good sending unit. All I need is a filler and an external pump to transfer gas.
Link to Pirate 4x4 Thread
Link to example tank on Amazon
Fenderfour
Member
Hi
Hi! Would you be able to post pictures of your stock rear and front ring & pinion gear as well as the carrier. Want to count teeths and opinion, as well as external ribs on the 3rds housing. Thx!
Fenderfour
Member
I've got it all packed up, crated, and buried in the shed currently. I can provide some info from the sales slip.
the front diff worked fine with standard Toyota 7.5" IFS gears. No problems there. The rear diff was a sort of a standard 8" (non-turbo). The external housing was a little different, and I would assume the carrier was also a little different, but I don't have specifics. I know that I needed to get a new rear housing. The carrier I had stock was replaced by an Eaton TruTrac. All of this was a normal installation on the existing axle shafts and housing. The shop said it would be easy to buy an old 4runner diff and swap parts in, including the carrier and housing. The V6/turbo/supra housing would fit up fine with a US market carrier.
Parts List:
Rear:
Eaton TrueTrac Toyota 8", V6 rear, 30 spline PN 913A610
8" Toyota Drop Out Case PN YPDOT8
Toyota 8" 4.10 Ratio 4Cyl Ring and Pinion, 27 Spline PN T8-410
Early 8" Pinion Kit PN PKT8-A
RPS V6 Carrier to 4Cyl Housing Bearing PN 32010x
Front:
Toyota 7.5" IFS 1990 & up with 50mm Carrier Bearing master overhaul kit PN 35-2042L
Toyota 7.5" 4.10 Ring & Pinion PN T7.4-4.11-NG
Seal PN 710419
Pinion Seal trail safe PN 301090-1-Kit