Turbo 700 in rockcrawling

[Baja Burley]

We have a T700 behind a 308 and I am wanting to know how it's going to hold up to serious crawling, ie upwards of 37's twin cases. It's in a Hilux so not too much weight on it. Few questions....
1. what do you do to protect the pan at the bottom?
2. How do you set up your 'downshift cable' the one connected to throttle position. Is looser or tighter better for crawling?
3. Is it going to last the punishment?

Cheers
Luke

[TURBO LS2]

Use a TH400

[rockcrawler31]

Actually i think with twin cases it'd be fine. The torque will be substantially less due to the cases, and it's going behind the same motor that it was designed for, in a vehicle lighter or at least similar weight than it was designed for.

What sort of HP are you looking at running this 308 at?

Do you need a rebuilt 700? i've got one here i'm swapping for a manual

[91Mav]

Use a TH400

The t400 has a taller (2.5ish) first gear and no overdrive compared to the t700's first gear of 3.1ish and a 0.7 overdrive. I know you said for rockcrawling but the overdrive helps with low diff and t/c gearing.

The t400 is a stronger box but the t700 can be built to handle the grunt. I'm currently building a 4L60E (electronically controlled t700) with new frictions, steels, band, seals, the Beast sun shell, Corvette sandwich plate and maybe Corvette servo's. I've been told to keep the standard servo's for 4wd purposes but couldn't make sense of the reasoning - anyone know? They can also be upgraded with the 5 pinion planet from a 4L65E but I'm not worrying about it for the V6. You might want to upgrade your t700 pump (likely 10 vane) to a newer 4L60E 13 vane pump.

To answer your questions:
1. Make a bash plate to protect it.
2. I'm not sure about the kick down cable as I'm going electric. I'd be manualising the t700 as heaps of people seem to struggle to set it up properly. The Transgo kits are supposed to be good http://www.ebay.com.au/itm/TRANSGO-STAG ... 3cc25831c1" onclick="window.open(this.href);return false;
3. You mentioned twin transfers? The extra gear reduction after the box will help it survive. You can also look at building with better parts as I mentioned above.

Have a read of http://helpwrench.com/forums/showthread ... and-Tricks" onclick="window.open(this.href);return false; if you wanna give it a go yourself.

[Willy Hilux]

Buy the time you spend the money on a built dual case setup, I'd be looking at going to an atlas.

[Modified Toy]

We have a T700 behind a 308 and I am wanting to know how it's going to hold up to serious crawling, ie upwards of 37's twin cases. It's in a Hilux so not too much weight on it. Few questions....
1. what do you do to protect the pan at the bottom?
2. How do you set up your 'downshift cable' the one connected to throttle position. Is looser or tighter better for crawling?
3. Is it going to last the punishment?

Cheers
Luke

700 would be fine and 4l60e full manual would be better

1.make a bash plate for the transfer/transmission
2. the cable is not a downshift cable it is for tv pressure and this is releative to line pressure,get this wrong the transmission will not be healthy,if you move the outer cable towards throttle body you get early shifts,move it away it gets later.(within reason)

[Modified Toy]

Use a TH400

The t400 has a taller (2.5ish) first gear and no overdrive compared to the t700's first gear of 3.1ish and a 0.7 overdrive. I know you said for rockcrawling but the overdrive helps with low diff and t/c gearing.

The t400 is a stronger box but the t700 can be built to handle the grunt. I'm currently building a 4L60E (electronically controlled t700) with new frictions, steels, band, seals, the Beast sun shell, Corvette sandwich plate and maybe Corvette servo's. I've been told to keep the standard servo's for 4wd purposes but couldn't make sense of the reasoning - anyone know? They can also be upgraded with the 5 pinion planet from a 4L65E but I'm not worrying about it for the V6. You might want to upgrade your t700 pump (likely 10 vane) to a newer 4L60E 13 vane pump.

To answer your questions:
1. Make a bash plate to protect it.
2. I'm not sure about the kick down cable as I'm going electric. I'd be manualising the t700 as heaps of people seem to struggle to set it up properly. The Transgo kits are supposed to be good http://www.ebay.com.au/itm/TRANSGO-STAG ... 3cc25831c1" onclick="window.open(this.href);return false;
3. You mentioned twin transfers? The extra gear reduction after the box will help it survive. You can also look at building with better parts as I mentioned above.

Have a read of http://helpwrench.com/forums/showthread ... and-Tricks" onclick="window.open(this.href);return false; if you wanna give it a go yourself.

Instead of the beast use the sonnax smartshell better idea and design http://www.sonnax.com" onclick="window.open(this.href);return false; as for the servos use superior both parts they work well togeather.

[Micka]

The T700 will be fine. For rock crawling you'll mostly be selecting 1st gear in the hard sections. There were a few buggies with T700 boxes and they performed quite well. As others have said, build a bash plate to save the sump.

Buy the time you spend the money on a built dual case setup, I'd be looking at going to an atlas.

Have to agree with this.

Hilux crap is...well...crap. You're going to end up way longer than an Atlas. Nowhere near as strong. And to have your cases handling the brutality of rock crawling (which they don't) you'll be upgrading every part possible. Then you'll want a disconnect for the rear. Then the front.


Just buy an Atlas and put it behind your T700.

[-Scott-]

Actually i think with twin cases it'd be fine. The torque will be substantially less due to the cases, and it's going behind the same motor that it was designed for, in a vehicle lighter or at least similar weight than it was designed for.

Slightly OT, but I'm hoping somebody can educate me.

I've always thought that the max torque seen by a gearbox is determined by the engine - not the downstream gearing. Sure, in some circumstances, weaknesses downstream may be the ultimate limitation (i.e. something fails before the gearbox limit is reached) but if we're talking about a gearbox (i.e. TH700) bolted to an engine for which it is designed (308, presuming it's not significantly developed) does it matter how many cases or what tyres are downstream? The torque in the TH700 comes from the engine - not the transfer case or the tyres.

I expect I'm missing something. What is it?

[Willy Hilux]

I wasn't comenting that the dual cases will be an issue with the T700. I was just stating that by the time you get 2 transfer cases, dual adaptor, adaptor to gearbox, cromo output and maybe a rear disconnect the $$$ will start adding up. Then you will need to carry a spare to comps because you will have the fear of breaking one. So thats 3 transfers you will need to get. Shit just buy an Atlas and be done with it.

[ethann]

I wasn't comenting that the dual cases will be an issue with the T700. I was just stating that by the time you get 2 transfer cases, dual adaptor, adaptor to gearbox, cromo output and maybe a rear disconnect the $$$ will start adding up. Then you will need to carry a spare to comps because you will have the fear of breaking one. So thats 3 transfers you will need to get. Shit just buy an Atlas and be done with it.

I've just recently went through the duals vs atlas.
I accuired two cases for free, even with doing that, if you build them properly the cost is only just shy of an atlas (everything new, marlin gear, RDC, chromo outputs, rebuild kits (plus shipping) etc).
In saying that, second hand can get alot cheaper and probably cheaper options.
But a lux case will never have the strength of an Atlas.

For my application, I am choosing an Atlas, mainly for length of driveline. I don't know how to handle long things . And overall strength.

Just my 2cents =)

[Baja Burley]

I'm not too worried about length in the driveline. To throw a spanner in here, I'm going to be running gears in a single case for now. This with the auto should give a good enough crawl speed on 37's. What is an atlas worth?

[Slunnie]

Actually i think with twin cases it'd be fine. The torque will be substantially less due to the cases, and it's going behind the same motor that it was designed for, in a vehicle lighter or at least similar weight than it was designed for.

Slightly OT, but I'm hoping somebody can educate me.

I've always thought that the max torque seen by a gearbox is determined by the engine - not the downstream gearing. Sure, in some circumstances, weaknesses downstream may be the ultimate limitation (i.e. something fails before the gearbox limit is reached) but if we're talking about a gearbox (i.e. TH700) bolted to an engine for which it is designed (308, presuming it's not significantly developed) does it matter how many cases or what tyres are downstream? The torque in the TH700 comes from the engine - not the transfer case or the tyres.

I expect I'm missing something. What is it?

Perhaps if the engine had no reciprocating mass.