advice needed - lj70 on volvo 303 portal axles

[SimonInAustralia]

Portal axles lift the diff centre and axle tubes 4.5 inches (in the case of Volvo portal axles), so 4.5 inches of extra clearance under the diffs/axles compared to normal non-portal axles.

Suspension and body lifts leave the diffs/axles in the same place, you get no additional clearance under them, they only lift the body/chassis.

 

[kallehzj78]

Hi,i bought a propshaft park brake from finland.

TOYOTA HJ, BJ, LJ KÄSIJARRU SARJA

Send Timo an email in english and he will answer,if you have problems to understand finnish...

I am going to convert my KZJ to c303 axels,you can see pictures of other parts from Offroadtarvike in my built up thred on 4x4sweden.

4x4sweden.se :: Läser ämne - Den lille svarte

 

[moonsy]

Portal axles lift the diff centre and axle tubes 4.5 inches (in the case of Volvo portal axles), so 4.5 inches of extra clearance under the diffs/axles compared to normal non-portal axles.

Suspension and body lifts leave the diffs/axles in the same place, you get no additional clearance under them, they only lift the body/chassis.

oh thats pretty cool

 

[cicak]

To answer your question

1. VOlvo axles give you 4-4.5 inches of extra space under your diff as the differential is in line with the top of the wheel and no longer in the middle of the wheel diameter. Great for Rocky terrin or deep ruts.
2. Using a lift kit never gives you extra diff clearance it just lets you put bigger sneakers underneath or allow greater body cleraance from terra firmer but increases COG normally unless you put offset rims on to compensate
3. Volvo axles reduce wheel travel enourmously - as the wheel travel is limited - soft tire pressures help but they BOUNCE on potholes and BUMPS .
4. They are very HEAVY usually 360kg + per axle.
5. tHEY normally require conversion to remove the crappy Landrover drum brakes and replace with Toyota DISCS etc or whatever is common you that part of the world. THey required a DRIVESHAFT handbrake also
6. Volvo axles have very low ratios and are a pain for long distance travel even with the high ratio pumpkins (else the portal cogs overheat and start disintergrating) installed 5.00:1 e.g. mine is 3000rpm at 66kph and 75-80kph at 4000rpm so I cruise at 66kph.
6. CHeck Hummer and you will see they copied the same 3 cog portal axle system but moved the DISCS brakes inboard to get around the BRAKES in mud issue I assume and easier mainteenance.
7. Vovlo axles were design for Leafs however conversion to coil has been done many times but it does lift the jaloppy up quite high to give suspension travel.

 

[SimonInAustralia]

2. Using a lift kit never gives you extra diff clearance it just lets you put bigger sneakers underneath

But one of the results of bigger sneakers is extra diff clearance.

3. Volvo axles reduce wheel travel enourmously - as the wheel travel is limited - soft tire pressures help but they BOUNCE on potholes and BUMPS.

Don't agree with that.

If being used as replacement axles for something like a Land Cruiser, and using the existing suspension components in that Land Cruiser, then they should have exactly the same wheel travel as the original axles provided.

As fitted as standard to a Volvo truck, they do not have much wheel travel, but that is due to the leaf suspension setup in the Volvo, not due to the portal axles themselves.

4. They are very HEAVY usually 360kg + per axle.

Nope, the Volvo portal axles are approximately 170kg for the front axle, and approximately 155kg for the rear axle, for a total of approximately 325kg.

Unimog portal axles are a lot heavier.

6. Volvo axles have very low ratios and are a pain for long distance travel even with the high ratio pumpkins (else the portal cogs overheat and start disintergrating) installed 5.00:1 e.g. mine is 3000rpm at 66kph and 75-80kph at 4000rpm so I cruise at 66kph.

The 'fast' Volvo portal axle overall ratio (combined pumpkin and portal reducation gears) is 5.99:1, the other ratios are 7.10:1 and 7.56:1.

The 5.99:1 ratio Volvo portals apparently have no problem cruising at highway speeds of 110-120kph, you just need to use a combination of larger tyres and/or transfer gear changes and/or transmission gear changes, to bring the engine rpm's back down closer to what they would be with standard axles.

 

[gotoy]

The 'fast' Volvo portal axle overall ratio (combined pumpkin and portal reducation gears) is 5.99:1, the other ratios are 7.10:1 and 7.56:1.

The 5.99:1 ratio Volvo portals apparently have no problem cruising at highway speeds of 110-120kph, you just need to use a combination of larger tyres and/or transfer gear changes and/or transmission gear changes, to bring the engine rpm's back down closer to what they would be with standard axles.

Cicak is running an actual Volvo 303. I dunno if it 110 would be possible but you wil certainky have to change the ratios; transfer or whatever.

I am not not an expert on volvo axle conversion but I have seen many a planned project end up on the scrap heap on completion due to the volvo axle ratio syndrome. The projecteer expected good speeds at good rpm, but at the end of the day only a mundane speed of 60 to 70kmph was possibe at acceptable rpm.

 

[SimonInAustralia]

Cicak is running an actual Volvo 303. I dunno if it 110 would be possible but you wil certainky have to change the ratios; transfer or whatever.

This thread is about putting Volvo axles under a 70 series Land Cruiser, this is a 70 series Land Cruiser forum, so doesn't matter what Cicak is running under his Volvo truck, this is how it relates to them going under a Cruiser.

Cicak is running either 7.10:1 or 7.56:1 ratio axles at the moment, so would have to change them to 5.99:1 ratio (as he plans to do), and would most likely have to improve the performance of the Volvo engine to give it enough power, to get his Volvo truck up to those speeds.


Under a Cruiser, Volvo portal axles with 37's and overdrive high range transfer gears, and/or with the fitting of a higher overdrive 5th gear, will bring the speed/rpms back close to standard, and will happily do 110kph just like a standard Cruiser.

I have some Volvo portal axles that are nearly ready to install, I have researched it for the past couple of years, I have done the calculations for tyre sizes, transfer gear ratios, and overdrive 5th gear ratios, and it isn't going to be a problem.

I am not not an expert on volvo axle conversion but I have seen many a planned project end up on the scrap heap on completion due to the volvo axle ratio syndrome. The projecteer expected good speeds at good rpm, but at the end of the day only a mundane speed of 60 to 70kmph was possibe at acceptable rpm.

Well they didn't know what they were doing then. They were obviously not running 'fast' 5.99:1 ratio axles with decent size tyres. Even without the overdrive transfer gears and/or higher overdrive 5th gear, it would have done much more than 60/70kph at acceptable rpm.

I know what the options are for the axle, transfer, and transmission gear ratios, it is easy to calculate what ratios will give what rpms at what speeds, and it is easy to get the speed/engine rpms back close to standard.

Get the combined transmission/transfer/axle/tyre ratio back close to standard, and there is no reason that it will not do the same speeds that it did before the axle conversion, it is simple mathematics.

 

[gotoy]

But one of the results of bigger sneakers is extra diff clearance.



Don't agree with that.

If being used as replacement axles for something like a Land Cruiser, and using the existing suspension components in that Land Cruiser, then they should have exactly the same wheel travel as the original axles provided.

As fitted as standard to a Volvo truck, they do not have much wheel travel, but that is due to the leaf suspension setup in the Volvo, not due to the portal axles themselves.



Nope, the Volvo portal axles are approximately 170kg for the front axle, and approximately 155kg for the rear axle, for a total of approximately 325kg.

Unimog portal axles are a lot heavier.



The 'fast' Volvo portal axle overall ratio (combined pumpkin and portal reducation gears) is 5.99:1, the other ratios are 7.10:1 and 7.56:1.

The 5.99:1 ratio Volvo portals apparently have no problem cruising at highway speeds of 110-120kph, you just need to use a combination of larger tyres and/or transfer gear changes and/or transmission gear changes, to bring the engine rpm's back down closer to what they would be with standard axles.

This thread is about putting Volvo axles under a 70 series Land Cruiser, this is a 70 series Land Cruiser forum, so doesn't matter what Cicak is running under his Volvo truck, this is how it relates to them going under a Cruiser.

Cicak is running either 7.10:1 or 7.56:1 ratio axles at the moment, so would have to change them to 5.99:1 ratio (as he plans to do), and would most likely have to improve the performance of the Volvo engine to give it enough power, to get his Volvo truck up to those speeds.


Under a Cruiser, Volvo portal axles with 37's and overdrive high range transfer gears, and/or with the fitting of a higher overdrive 5th gear, will bring the speed/rpms back close to standard, and will happily do 110kph just like a standard Cruiser.

I have some Volvo portal axles that are nearly ready to install, I have researched it for the past couple of years, I have done the calculations for tyre sizes, transfer gear ratios, and overdrive 5th gear ratios, and it isn't going to be a problem.



Well they didn't know what they were doing then. They were obviously not running 'fast' 5.99:1 ratio axles with decent size tyres. Even without the overdrive transfer gears and/or higher overdrive 5th gear, it would have done much more than 60/70kph at acceptable rpm.

I know what the options are for the axle, transfer, and transmission gear ratios, it is easy to calculate what ratios will give what rpms at what speeds, and it is easy to get the speed/engine rpms back close to standard.

Get the combined transmission/transfer/axle/tyre ratio back close to standard, and there is no reason that it will not do the same speeds that it did before the axle conversion, it is simple mathematics.

Cicak is using 5.xx ratios and reports he doing 66kmph at an acceptable rpm. I was using that as a reference.

Perhaps the calculations were wrong, perhaps they did not have the $$$ (or had but did not want to spend). However I have seen this happen twice now; once on a wrangler (yeh yeh this is a 70's forum) using 7.xx and once on a 70 series using 5.xx.

For this one, will have to await your actual field test report.

 

[SimonInAustralia]

Cicak is using 5.xx ratios and reports he doing 66kmph at an acceptable rpm. I was using that as a reference.

No, Cicak is not using 'fast' 5.99:1 ratio axles. I have discussed it with him.

He is using 7.10:1 or 7.56:1 ratio axles, in a Volvo truck with standard Volvo 4 speed transmission with 1:1 4th gear, so no 5th gear overdrive that you get in Cruisers.

Those two reasons, 7.? ratio axles and 4 speed transmission, are why he only gets 66kph.

The specs for the 'fast' 5.99:1 ratio Volvo trucks give a max cruising speed of 100kph at 4000rpm, and max speed of 125kph, with the 1:1 4th gear in the 4 speed gearbox.

Perhaps the calculations were wrong, perhaps they did not have the $$$ (or had but did not want to spend). However I have seen this happen twice now; once on a wrangler (yeh yeh this is a 70's forum) using 7.xx and once on a 70 series using 5.xx.

Not surprising if they were using 7.10 or 7.56 ratio axles in the Jeep.

Maybe they didn't want to run larger tyres such as 37's, and consider overdrive transfer gears and/or a higher overdrive 5th gear in their transmission, in the 70 series Cruiser. Without exact specs of what they were using, it is impossible to say where they went wrong.


In my HZJ78, the calculations are...

Standard Toyota axles + standard transmission + standard transfer on 32" tyres = 2587rpm @ 110kph in 5th

5.99:1 Volvo Axles + higher overdrive 5th gear in transmission + standard transfer on 37" tyres = 2585rpm @ 110kph in 5th (gives underdriven 1-4 gears compared to standard, 5th gear same as standard, higher gap between 4th and 5th)

5.99:1 Volvo Axles + standard transmission + overdrive transfer on 37" = 2867rpm @ 110kph in 5th (gives all 5 gears underdriven compared to standard, but with same spread between gears)

5.99:1 Volvo Axles + overdrive 5th transmission + overdrive transfer = 2378rpm @ 110kph in 5th (gives underdriven 1-4 gears, and overdriven 5th)


...so, I can get very close to standard gearing at highway speed, with slight compromises in terms of gear spread and overdrive/underdrive amongst the 5 gears depending on which option is chosen.

I am still not sure which is the best option at the moment.

If you are interested, the gear calculations can be seen here...
http://i267.photobucket.com/albums/...l Axles/VolvoPortalAxleHZJ78gearratiocalc.jpg

 

[glazariu]

i did some field tests with only the rear axle fitted , and the 33' tires i m obliged to use in the championship and the result is more than i expected ..... probably i will run max 110 kmh , but that s ok ... i m doing this car for competitions only ....

hope next w/e i ll have the front fitted aswell.... and some picture / movies

 

[SimonInAustralia]

i did some field tests with only the rear axle fitted , and the 33' tires i m obliged to use in the championship and the result is more than i expected ..... probably i will run max 110 kmh , but that s ok ... i m doing this car for competitions only ....

hope next w/e i ll have the front fitted aswell.... and some picture / movies

What ratio are your Volvo axles?

If the maximum tyre size you can use is 33", and you do want to go faster, probably only option is overdrive high range/under drive low range transfer gears.

Really depends on the type of competitions you are using it in as to whether you need to or not.

Looking forward to the photos and videos!

 

[glazariu]

the axles are 5.99

there are 3 cathegories of cars accepted in the romanian championship .... standard - no modifications
open - max tires 33 and rollcage, etc...
extrem - no restriction in tire size, etc .....


that s why i m using the 33' .... this year ... next year maybe i ll pass to extreme .... depends on my copilote ( i.e. my wife )

for the moment , only with the rear axle , i m satisfied how it moves

and to have an idea about this project, the next steps are :
- disk brake conversion
- front winch - gigglepin , fitted under copilote seat
- raer winch - come up 9500
- 2 batteries + IBS
- rollcage .... FIA model approved ...
- custom fuekl tank
and some other small things like HD clutch, CB station, helmets with communication system, fire extingusher, etc

 

[cicak]

Cicak is running an actual Volvo 303. I dunno if it 110 would be possible but you wil certainky have to change the ratios; transfer or whatever.

I am not not an expert on volvo axle conversion but I have seen many a planned project end up on the scrap heap on completion due to the volvo axle ratio syndrome. The projecteer expected good speeds at good rpm, but at the end of the day only a mundane speed of 60 to 70kmph was possibe at acceptable rpm.

yes correct mine is 7.56 something and low ratio.

4 speed is a big issue for me so 3000 RPM is what I limit myself to for noise and fuel economy. I trying to find a 5 speed gearbox from a C306 to no avail as I do not want to put a non original gearbox in only a non original engine .

Yes I am ordering a new pair of pumpkins to reduce the ratio to 5.99 but I still think it will be too low and I am also going to 37" sneakers. I have done the formulae . I just figure its going to be a slow hauler

 

[cicak]

This thread is about putting Volvo axles under a 70 series Land Cruiser, this is a 70 series Land Cruiser forum, so doesn't matter what Cicak is running under his Volvo truck, this is how it relates to them going under a Cruiser.

Cicak is running either 7.10:1 or 7.56:1 ratio axles at the moment, so would have to change them to 5.99:1 ratio (as he plans to do), and would most likely have to improve the performance of the Volvo engine to give it enough power, to get his Volvo truck up to those speeds.


Under a Cruiser, Volvo portal axles with 37's and overdrive high range transfer gears, and/or with the fitting of a higher overdrive 5th gear, will bring the speed/rpms back close to standard, and will happily do 110kph just like a standard Cruiser.

I have some Volvo portal axles that are nearly ready to install, I have researched it for the past couple of years, I have done the calculations for tyre sizes, transfer gear ratios, and overdrive 5th gear ratios, and it isn't going to be a problem.



Well they didn't know what they were doing then. They were obviously not running 'fast' 5.99:1 ratio axles with decent size tyres. Even without the overdrive transfer gears and/or higher overdrive 5th gear, it would have done much more than 60/70kph at acceptable rpm.

I know what the options are for the axle, transfer, and transmission gear ratios, it is easy to calculate what ratios will give what rpms at what speeds, and it is easy to get the speed/engine rpms back close to standard.

Get the combined transmission/transfer/axle/tyre ratio back close to standard, and there is no reason that it will not do the same speeds that it did before the axle conversion, it is simple mathematics.

Simon

your sums are correct. I need a 5 speed gearbox to achieve nice cruising speeds and economy.

Volvo axle converted trucks tend to sit higher because of the mount point for the suspension is 4.5" higher. Conversion to coils (not an issue for you) tends to make the body sit very high.

Your 1HZ will be fine pushing the axles along in 5th. Just remember they can overheat at high speeds. In snow or SAND it will be just awesome.

We cannot buy the RHD steering they will not sell it without selling the whole AXLE . So one tonne lorry steering arms and get the bend put into the bar.

at 3000rpm I get 5.2k/liter out of it on the highway and WORSE travelling in town and up and down steep short hills

 

[glazariu]

VOlvo from factory uses a LR transmission handbrake on the long shaft and it is very effective better than a YOTA handbrake. Yes you will have to sort out a handbrake.

We use LC II front DISCS and Pajero Discs on rear here.

I will send pics of my Volvo's front axle setup so you can see it. However it is setup for FOrward cab control.

i would really appreciate the picture for the disc brake conversion .... tx

 

[SimonInAustralia]

and to have an idea about this project, the next steps are :
- front winch - gigglepin , fitted under copilote seat
- raer winch - come up 9500

That is a big winch to fit under the seat!

Like to see photos of how you fit up the rear winch.

 

[SimonInAustralia]

Yes I am ordering a new pair of pumpkins to reduce the ratio to 5.99 but I still think it will be too low and I am also going to 37" sneakers.

Did you hear back from the guy in the UK making up the 5.99 cw&p's?

You need a 5th gear!

 

[cicak]

Did you hear back from the guy in the UK making up the 5.99 cw&p's?

You need a 5th gear!

Yes I been in contact with him sending him some money in stages soon for a set. Too busy growing my business assetts at present to fix up the Volvo

Yes I need a 5th gear and a grunty diesel engine (unfortunately 13B-T's have priced themselves out of the market here) and a change of pumkins

 

[glazariu]

finally, the front axle is in place

the final steerin will be fully hidraulic from PSC

until then , the volvo steering is enough ...

here are some pictures :

https://picasaweb.google.com/glazariu/Toyo?authkey=Gv1sRgCOq3qd_bjIP_2QE#

 

[glazariu]

next thing to do .... disk brake conversion .... a real headache