4wd vacum switch problem...

nzdncjw · Post by **nzdncjw** » Sun Jan 21, 2007 2:50 pm

Hey there - got a problem with my 4wd system - won't engage or disengage properly.

for some reasont he 4wd system doesn't work.... it has the FD switch on dash which switches i presume a vacum pump which engages the 4wd at transfer box via a diaphram. when you pull the switch you can hear everythin doing it s thing but it won't engage in 4wd BUT sometimes it does only not properly - start reversing and it pops out....

I checked all lines etc for leaks found one and sorted it. still sme problem so I thought I would pull the diaphram unit off the back ofte transfer box and see what is happening - when you flick the FD swtich it moves it about half way out and when you flick swtich again nothing happens.

this would sugest to me not enoguh vacum? how do I test or fix this problem?

With the diaphram unit removed from transfer box - only the shaft into transfer box remains you can engage and disengage 4wd easily and drive around.... so to me it rules out transfer box - everything seems to be doing its thing just not enough vacum.....

Thanks!

I am in Dunedin by the way...

nzdncjw · Post by **nzdncjw** » Sun Jan 21, 2007 3:48 pm

I have added some photos under nzdncjw photo album under users pictures to show the units involved and condition etc....

Thanks for any help to sort this out!

chris

4wdnuts · Post by **4wdnuts** » Sun Jan 21, 2007 5:10 pm

is it a deisel motor? if so the alternator has a vacuum pump on the back of it. take it to an auto sparky as they can check them to see if they are still working properly. i have spent ages trying to figure this system out on my mates surf and it was a right pain in the ass.

MATT4U · Post by **MATT4U** » Sun Jan 21, 2007 6:54 pm

what truck??? if its a cruzier is it 24volt? if so its a common prob, a friends truck has the same prob, we just change the vac lines round to engage 4wd. toyota charge a grand for new solinoids.

nzdncjw · Post by **nzdncjw** » Sun Jan 21, 2007 7:36 pm

Sorry, yes it is a fj40 cruiser SWB 1980 Diesel.

When you say changed them around? where did you do that? down under neath? are the solenoids the two cylinder things on firewall? is that the source of my problem?

Thanks

Chris

nzdncjw · Post by **nzdncjw** » Sun Jan 21, 2007 7:39 pm

its 24v as well....

I have a friend that is an auto sparky..... I'll give him a call and get him round to check it out....

The worst thing is I can't drive it on the road as it is still only a chassis and body with no seats or front gaurds windscreen etc.... I don't think mr Police man would take to me very nicely driving it along the road....
Chris

nzdncjw · Post by **nzdncjw** » Sat Jan 27, 2007 12:08 pm

I have done some more looking.... Went to the Toyota dealer yesterday ( a mate works there) He did some research for me. The solenoid is a discontinued part.... DOH! so that was a dead end.... BUT part number is 85440

He looked into it a bit further, from what he could tell he reckons there are two fixes for it. One is get vacum, alternater and solenoid all checked and tested and replace whatever. The second was to find a stuffed gear box from a cruiser that has the manual engaging 4wd ie via gear lever.... and do a swap. Looking at the diagrams on the two systems the gasket that these two parts fit onto the transfer box seems identicle and he reckons you could swap the whole gear lever system over? has anyone done this? or know if its possible?

I went along to the local 4wd parts man here in town (the only one!) to ask some questions about this - basically got a don't want to know about it answer 'wouldn't know sorry, you will have to play round your self, haven't looked at that for years!' this was from the boss! not very good service! so no luck there....

Anyway, if anyone has any more ideas I would be very keen to hear them....

chris

Jerry · Post by **Jerry** » Sat Jan 27, 2007 4:45 pm

Option 3 is to get a mechanical vacuum switch to replace this, my one on my Rugger just died...and rip out all the factory stuff, about $100 for the part apparantly

nzdncjw · Post by **nzdncjw** » Sat Jan 27, 2007 5:30 pm

that might be a good idea - I will investigate that one... Where did you get it from?

thnanks!

Chris

Jerry · Post by **Jerry** » Sat Jan 27, 2007 5:47 pm

Andrew in CCVC (other club I belong to...), he has a seriously modified FJ40 and a really good mechanic......

http://forum.ih8mud.com/showthread.php?t=61345

I can give you his number if you want to give him a call...

Jerry · Post by **Jerry** » Sat Jan 27, 2007 5:58 pm

I have 2 switches on the Daihatsu.....on the transfer case, one to engage and one to disengage, problem was that the breather attached to the air intake on the engage one was missing and it filled up with mud, Andrew managed to strip it and clean it....

The symptom was that it kept dropping out of 4wd, and then it just didn
t work, I'm hoping that its just the switch and not the gearbox....it appears to work....ie the 4wd light is on now.... :lol:

Is it clicking when it engages..or not?, the mechanical switch is an option for me as I'm guessing the new part from toyota (and thats even if its avaliable) will be megabucks....

nzdncjw · Post by **nzdncjw** » Sat Jan 27, 2007 6:30 pm

Hello, I have totally pulled all the air lines off the truck and checked the whole system as best as I could.... everything seems to be in good nic - there was a small air leak but I fixed that with a hose clamp - there wasn't one....

The symtpoms of it are this - when the truck is running I pull the switch and you can here the clunk of the solenoid then the vacum thing doing its bit.

If I reverse it clicks a bit as though its not engaged then it slips out of 4wd seems to be the same in forward.... then its out and you have to push and pull the switch to get it back in BUT it doesn't always work....

testing for me is limited because I only really have the front lawn and that is so far from flat and even its not funny.... but good to see if 4wd is working as it is easy to lift a wheel off the ground.

4wdnuts · Post by **4wdnuts** » Sun Jan 28, 2007 7:36 pm

just on a completly different idea are you sure the front diff isnt stuffed. ie when no load on it its ok but when it loads up the teeth are slipping past each other? just another idea to think of

nzdncjw · Post by **nzdncjw** » Sun Jan 28, 2007 9:34 pm

hope not..... I don't think so the problem with the 4wd has been an ongoing problem for a long time now working and not working and so forth.... just while I was pulling the truck to bits I thought I am going to nail this problem once and for all

Short of pulling the diff apart is there an easy way to check that?

Thanks

nzdncjw · Post by **nzdncjw** » Wed Feb 07, 2007 9:41 pm

latest update on my 4wd system.... Still havn't got it totally running. I priced a mechanical vacum pump as sugested by someone on here I think but it was nearly $300.... a bit steep!! But I have managed to track down (well about 85%) a Transfer case that is stuffed with hopefully all the linkage etc still on it to convert my truck to a manual 4wd shift with a lever.... the way it should be! I found out through Toyota that the manual system should bolt straight on to transfer box 'in theory' so hopefully that is the case otherwise I will have to make it work....

Just waiting for the guy to go check it.... looking positive....

Thanks for all those who helped...

Chris

Jerry · Post by **Jerry** » Wed Feb 07, 2007 9:46 pm

Theres an air tool pump thingy you can use to test it forst to see if its really the problem......is that price trade or retail?

nzdncjw · Post by **nzdncjw** » Wed Feb 07, 2007 9:54 pm

That price was trade (through Repco)

What is the 'air tool thingy' I can use to test it? and if I get one of these tools how do I do the test?

Thanks!

Chris

roscoFJ73 · Post by **roscoFJ73** » Thu Feb 08, 2007 1:49 am

nzdncjw wrote:That price was trade (through Repco)

What is the 'air tool thingy' I can use to test it? and if I get one of these tools how do I do the test?

Thanks!

Chris

Its a vaccum gauge. Im not sure how much pressure they require ,but my FJ73 only needs 7psi according to the manual to shift the t/case.
You just plug it into the vaccum source and start the engine and read the gauge

I presume it has 2 hoses,if so try swapping them over. On will be off,off will be on.
It may isolate the problem between vaccum and t/case.
The solenoids are used on other toyotas ,not sure which model or whereabouts on the car.
A wrecker may recognise them

If your vaccum pump was worn out ,you may also have problems with enough vaccum to operate the brakes.

As to changing it to a manual shift,on mine its quite a job. You have to dismantle the t/case and fit the the front half of a manually shifte t/case casing.
IMO you would be better off seeing if you can fix the vaccum problem if it has one :wink:

BrentC · Post by **BrentC** » Thu Feb 08, 2007 7:45 am

so, I assume that would be why my 1988 70 series is staying in 4wd :?:

nzdncjw · Post by **nzdncjw** » Thu Feb 08, 2007 4:01 pm

I have the pictures of all the exploded views of both the manual system and the vacum system and from what I can see I should be able to just swap the linkage over without pulling the transfer case apart....

While in one way I would like to fix the problem with vacum etc (brakes seem to be working sweet...) I like the idea of having a totally manual system where I know it is in 4wd or not.... less electronics to play up later on too....

Chris

roscoFJ73 · Post by **roscoFJ73** » Thu Feb 08, 2007 6:12 pm

nzdncjw wrote:I have the pictures of all the exploded views of both the manual system and the vacum system and from what I can see I should be able to just swap the linkage over without pulling the transfer case apart....

While in one way I would like to fix the problem with vacum etc (brakes seem to be working sweet...) I like the idea of having a totally manual system where I know it is in 4wd or not.... less electronics to play up later on too....

Chris

I might be wrong but I thought the part of the t/case where the linkage joins on is different.
Maybe you have the older type t/case,Im now getting a visual in my head of the old t/case

I like my vac shifter on the 73 series. On my 75 series the manual shifter is in a awkward place and when its in LOW it rubs against my leg

nzdncjw · Post by **nzdncjw** » Mon Oct 08, 2007 7:43 pm

I'm back again... After a long while my FJ40 Cruiser is finally all road legal! Just in time too! Just had a 2nd addition to the family and My wife wasn't so keen on being stuck at home all day without transport!

Anyway, I have done a bit of playing. The situation is this, When 4wd is engaged ie hubs locked and switch switched. There is still no '4wd' I have a cover off so I can see the front drive shaft when driving, the drive shaft spins so drive 'should' be going to the front wheels, but there is no drive? the only options I can think of is.

1. Diff?
2. CV Joints?
3. Hubbs

I recently had all the axle seals done on the truck at my local garage and they had the axles all apart - I would have thought the garage would have mentioned the cv joints if they were gone when they had everything apart? (This is a good garage...)

It leaves me either Diff or Hubbs? how can I test either of these to find out whats what....

Any other Ideas?

The vacuum issue is still there but not my biggest concern at this stage....

Thanks heaps!!!

Chris

Mattman · Post by **Mattman** » Mon Oct 08, 2007 8:21 pm

If you unlock the hubs and put it in 4wd does the front driveshaft still turn?

If so the transfer case is engaging correctly and your problem is with the front diff however I suspect it's most likely the transfer case not engaging correctly.

Matt.

nzdncjw · Post by **nzdncjw** » Mon Oct 08, 2007 8:27 pm

Yes the front drive shaft still turns...

Mattman · Post by **Mattman** » Mon Oct 08, 2007 8:35 pm

With the truck in 2wd jack one of the front wheels off the ground.

With the hubs locked turning the wheel in the air should cause the diff and driveshaft to rotate.

Matt.

MNC · Post by **MNC** » Mon Oct 08, 2007 8:44 pm

nzdncjw wrote:...The second was to find a stuffed gear box from a cruiser that has the manual engaging 4wd ie via gear lever.... and do a swap. Looking at the diagrams on the two systems the gasket that these two parts fit onto the transfer box seems identicle and he reckons you could swap the whole gear lever system over? has anyone done this? or know if its possible?

So have you decided not to switch to a manual 4wd actuator? If so why?

I'm looking at replacing the vacumn operated diaphram unit on my transfer case (out of a 88 LJ 71 land cruiser) with a manual system as it does not fit inside the chassis rails and I want it lower. Will be working on this shortly but also keen to hear from other that have done this mod.

nzdncjw · Post by **nzdncjw** » Mon Oct 08, 2007 8:59 pm

I decided not to as I was told by several people that the older manual style transfer shifter box (that I got hold of - early 70's I think) is no where near as strong as the later model version that i have (1980) I was recommended to fix what I had as it is a stronger unit.

Kinda wish I did just swap it all over in the end as the problem would have been fixed...

Chris

swampasurf · Post by **swampasurf** » Tue Oct 09, 2007 12:42 pm

I am in the middle of putting an early '90s Prado transfer case in my Hilux and have noticed the 4WD selection is very similar to this. Its got all the same parts, just looks a little different in the layout of it all.
I am going to adapt an air ram to the T/C to get rid if the whole selector assembly.
Might be something to look at for you? But most likely would be easier to fix the vacuum activation as the T/C needs to be split to do the air ram.

BrentC · Post by **BrentC** » Tue Oct 09, 2007 12:52 pm

yep - check that you have vacuum from alternator - then from each solenoid all the way to the case - if pipes etc ok - isolate which solenoid faulty by swapping hoses over and pushing the buttons etc - I ended up using a 2nd hand solenoid to replace faulty one (from off ORE and Just Cruisers) - even though I had a local compressor place make up a set of new 24v solenoids that worked well - now in my spare parts box

nzdncjw · Post by **nzdncjw** » Tue Oct 09, 2007 9:16 pm

what a good and easy to check the vacum from alternator?

thanks

4wd vacum switch problem...

4wd vacum switch problem...

added some photos

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