T700 Auto install, gear ratio issue

[Da Chad]

Fellas

Iv got a dual cab Hilux and Iv put a 350 chev under the bonet and running it through a turbo 700 auto 4 speed gear box, the issue I now have, going from a manual to a auto is that my gear ratios are out by a long way. Im doing 5k in top gear and doing 80km/hr, very frustrating!

I had a few ideas, including cutting ford 9in diffs in the front and rear, cause you can get a wide range of ratios, but due to the cost of $3500 each end and still having the original hilux axles and CVs iv pritty much ruled it out.

I don't know what ratios are available in patrol, landcruiser, hilux. I am open to a complete removal of hilux guts and installing coil spring setup from either landcruiser or patrol, due to the fact im paranoid that the V8 is going to munch all weak parts. and If I can kill multiple birds with one stone, that option will be on the cards

Has any one got any advice on what options are avialable to fix ratio and weakness issues.Cheers

[sprungupcruiser]

what is your current diff ratios?

[Dirty]

If you look at going the Ford 9" route, get the outers of some Dana-60's and run 35-spline 9" centre. With a little planning you should be able to get off the shelf axles from the US to fit in as the D60 comes in a heap of widths and pumpkin offsets.

Hi9 do a high pinion front which will set you back about US$1,600 with ratio for the front. Or you can modify a standard front 3rd.

Search on Pirate4x4.com for "609".

- David.

[Da Chad]

If you look at going the Ford 9" route, get the outers of some Dana-60's and run 35-spline 9" centre. With a little planning you should be able to get off the shelf axles from the US to fit in as the D60 comes in a heap of widths and pumpkin offsets.

Hi9 do a high pinion front which will set you back about US$1,600 with ratio for the front. Or you can modify a standard front 3rd.

Search on Pirate4x4.com for "609".

- David.

Dav
Excuse my ignorance, but Danas' are what. are they a small truck line, and are the parts readily available in OZ. They sound like a good option.

going by the photos seems like people have brought parts nd got some heavy fabrication happening. Im a tradie but got no gear for that kind of work.

Have you worked with this equipment and if you have howd you go with mods to existing car? swing arms, shock mounts, spring mounts,etc?

[hulsty]

5000rpm is really high, even with steep diff ratios, are you sure the box is getting into top gear/ over drive? is a TH700 a over drive box?

[simkell]

The ratio for a lux 5 speed box are

1-3.625
2-2.043
3-1.394
4-1.000
5-0.802

Turbo 700 4 speed auto ratio
1-3.06
2-1.62
3-1.00
4-0.70

The turbo 700 has a taller overdrive than the 5 speed lux box, so you should be pulling less revs compared to your 5 speed manual.
Are you certain you are getting all four gears?
Is it sluggish on take off?
Is it slipping in any of the gears?

[Da Chad]

thanks for all the responses, im only new to this forum thing,its gud.

I found out that the diff ratios in the front and rear are 4.3:1.

And Im deffinatly getting all the gears. I brought a flogged out box, they are hard to get hold of when they are mechanically driven, bloody hell.Iv had it all rebuilt with the shortened shaft from marks adapters to mount the trasfer box, B&M valve body and shifter,etc. Im 100% that the box is doing what its suposed to do.

in response to the sluggish take off.What Iv found is that when im even driving around the road the take off is very jumpy and it wants to change gear very quickly, and at like 70km/hr im already in top gear,4th, so over drive is definatly working. I have counted the gear changes just to ensure im not missing a gear.

What do you guys think?

Im thinking I may need a ratio of maybe something around 3.2:1 ratio

[Da Chad]

In reponse to "simkell" you pose a valid arguement, is there any thing else you think that may affect the ratios besides the obvious, like tire size?

[simkell]

what is the stall of your convertor

[Willy Hilux]

Ya haven't got it in low range have ya.

Had a mate running 4.1:1 diffs with a V6 and turbo 700 in a lux.

[RED60]

Ya haven't got it in low range have ya.

Had a mate running 4.1:1 diffs with a V6 and turbo 700 in a lux.

This sounds more like the problem.... if everything is working properly there is no way that you will be pulling those revs at that speed in high range... it's mathematically not possible...... other possibilities have been mentioned, which point to something wrong with the drive line...

ps... you have to admit it if you're in low range so we can laugh... heh heh

[hulsty]

I vote your in low range!! or your not getting all the gears.

[RUFF]

Or your Tacho is set wrong.

[thrashlux]

Or your Tacho is set wrong.

yeah what tacho r u using??
if its a 4cl tacho it will be 2x what you are doing ie u say 5000 in top gear at 70k well thats 2500 at 70 which sounds right
but surely the engine sounds diferent at 5000 to 2500
so i vote low range
4.3 should be spot on with that overdrive and some bigger wheels

[Frankenyota]

Not unless he's running standard size tyres.
What tyre size are you running?

Matt

[Dirty]

Dav
Excuse my ignorance, but Danas' are what. are they a small truck line, and are the parts readily available in OZ. They sound like a good option.

going by the photos seems like people have brought parts nd got some heavy fabrication happening. Im a tradie but got no gear for that kind of work.

Have you worked with this equipment and if you have howd you go with mods to existing car? swing arms, shock mounts, spring mounts,etc?

Dana-60's or the D70 run the same spline and axle diameter as the 35-spline 9" centres. Ford F-trucks come standard with the Dana diffs.

I am currently gathering the parts to do this myself, but a search on Pirate will give you all the good oil on it.

And if you can weld it shouldn't be too hard to do it all yourself as long as you can use a tape measure and a welder. You could pay to have the D60 ends put on the 9" housing though if you weren't in the position to make up a jig to do it yourself.

This would give you a monster strong setup that wasn't as heavy as full D60's, and even with standard components will out last the rest of the driveline.

Just an option, 9" housings can be had for $200 off ebay and 3rds for around the same. Just need to hunt down the diffs out of a 4x4 F250/350 and look to any of the US sites for axles. The HD ARB lockers are 35-spline and then look for the gears.

Not as simple as buying all the gear off the shelf for the Hilux diffs, but will be a heap stronger.

- David.

[highersurf]

hi i have a 91 lux with vn v6 t700 auto and being diesel it has 4.55 diff centres. im sitting on about 2800ish at a 100 with 33's

[Da Chad]

Hey guys.

I have been to the mechanics just to check to see if I had a brain explosion and had the transfer case in low range. Its not! I haven't driven the car for a few months and just maybe when I drove it,it was in low range.

Im gettn the radiator back in the car in the next few days.

Il get back to you.

PS im running 35in Mickies, and I pulled a 2.8 diesel out of the car.

[Da Chad]

Also the tacho is a "super cheap" speacil till I get the car running properly. But your correct there is a difference in the sound a car puts out between 5k and 2.5K. Im sure it was closer to the 5K mark.

Again Il get the car going in the next few days and get back to you.

[Frankenyota]

I have 4.88 diff ratios and 35" tyres and my revs are around 2,500 at 100km.
What do you use for a speed sensor?
Also when i fitted my speco taco it had a switch on the back to set it for a 4,6, or 8 cylinder.

What transfer case are you running?
I would look at 60 series diffs to run with the 350, strong and cheap. 4.11 diff ratio's.
The rear diff is offset so will depend on the transfer your using.

Matt

[v6zookie]

have you hooked up the electrics for the over drive corectley so the overdrive kicks in at a decent rev range