View Full Version : Raffle Rig 4wd help

04-12-2008, 05:46 PM
Hey guys, I posted this on the main board but Hoped i could catch you guys over here possibly for some help. went for the inaguaral Wheel in the Raffle Rig today and I could not get 4wd to engage, I tried everything and then some. need a redemption ride bad but i wanna get this figured out. Can you help!! Again guys, this ride is awesome and I drive it about everyday for work. It runs great and gets alot of looks. Thanks in advance for the help!!


04-12-2008, 06:49 PM
As one of the last two people to address this problem, I can say with some assuredness that the problem lies in the diaphragm cylinder which converts the vacuum from the 4WD solenoids to motion of the shift fork which engages the front axle. We thought we had the problem solved but obviously not. Replacing the diaphragm should cure the problem but there are some tests, noted in the FSM, that pinpoint whether the diaphragm is bad. What is happening is that the vacuum is good to the diaphragm but the diaphragm isn't creating enough movement of the front drive shift fork shaft to engage the front axle. Everything else checks out good, hubs, solenoids etc. and I hope you can fix the problem easily. Sorry we didn't get it right.
Steve Crase

04-12-2008, 07:07 PM
cool. I really appreciate the help! I was underneath there this afternoon when i got home familiarizing myself with things and I think its something i can take apart and fix myself. I am very grateful for the awesome truck i won and this helps me so i can just go straight to the source of the problem. Thanks Steve.

04-12-2008, 07:31 PM
Was the Cruiser FSM included with the other booty that came with the truck? If not, get a Haynes at the very least but the Toyota FSM for about $69 is the best money you can spend for learning maintenance and fixes the truck will require. Avoid the Chilton's - it's toilet paper compared to the other two. Be sure to buy an '89 or '90 Toyota FSM - leave the '88 alone as it is mainly an addendum to the '84 Heavy Duty Land Cruiser manual.

04-13-2008, 01:40 AM

We are all SUPER jealous you won the rig :thumb: - You could always drive out here and let the club wrench on it for you but if you do, be forewarned that Ige may not let you leave with the rig :hill:

Steve, great information and thanks for posting that up. Hopefully Josh will be able to fix it easily and start hitting the trails!!

04-13-2008, 07:27 AM
I didnt get a FSM, no, I do have a haynes manual though from when I used to have an early fj80. I was flipping thru it and from the info i saw on mud combined, i think i have enough info to at least get started and try to generate questions from there. If i take the diaphragm completely out will the truck still be operable in 2wd or will this park me for a few days while it gets worked on?

04-13-2008, 07:28 AM
and I would love to be out there! my goal is to get out there this year or next to experience some CO 4wheeling.

Uncle Ben
04-13-2008, 08:51 AM
I didnt get a FSM, no, I do have a haynes manual though from when I used to have an early fj80. I was flipping thru it and from the info i saw on mud combined, i think i have enough info to at least get started and try to generate questions from there. If i take the diaphragm completely out will the truck still be operable in 2wd or will this park me for a few days while it gets worked on?

Do you have access to a hand vacuum pump? A lot of parts stores have tools like this available for rent/use. Before taking the diaphragm assembly off verify the diaphragm is not holding vacuum. I believe your problem lies in the vacuum solenoid array but you need to first verify the diaphragm is not leaking.
Yes, if you pull the vacuum diaphragm assembly off your truck will be staying parked for a little while. The lever assembly is gear lube bath so you will loose some lube after the assemble is loosened.

04-13-2008, 10:32 AM
The last time Ige and I checked the truck out, we used a vacuum pump and gauge and were able to confirm that the diaphragm held vacuum in both directions and that both the 4WD solenoids were functioning correctly. We also know that the shift link lever in the diaphragm cylinder is moving and not stuck. The problem appears to be that the diaphragm, with the normal level of approx. 15" of vacuum applied to it occasionally doesn't move the front drive shift fork shaft quite far enough to fully engage the front drive clutch hub sleeve to the front output shaft. With closer to 20" of vacuum the axle engaged every time. That some grinding is heard when the front axle should be engaged is indication that the sleeve isn't moving quite far enough, at least in my mind, with the normal level of vacuum applied. There is a test described in the FSM that measures the stroke of the diaphragm cylinder assembly. I think it should be the first thing to check as it will either indicate the diaphragm is the culprit or that the problem is internal to the t-case.

04-13-2008, 10:41 AM
I know that advanced auto parts has a rental program so I will see if they have a vaccum pump. If its not getting it to move all the way with the normal amount of vaccum, but it is engaging some and the sleeve is moving some, how would I either increase the vaccum or get that sleeve to move all the way? will this be something that would entail dropping the transfer case and making adjustments thru the system to get it to slide in place to engage the front?

I have a decent mechanic here that I use for my 40 sometimes, if this gets more detailed, It looks like i may have to take it to him. I am limited on tools, knowledge and space.

04-13-2008, 10:51 AM
Increase vacuum? That would be a workaround that isn't required if the systems are all up to snuff. Try to imagine the diaphragm being stretched out of shape, distorted, so that when normal vacuum is applied it doesn't move the shift links as far as it should. I suggest focusing on that before thinking about pulling the t-case apart. Start with the obvious simple stuff. Does your Haynes show pictures of the diaphragm cylinder assembly?

04-14-2008, 07:25 AM
ok I have located a buddy who has a Vaccum pump and I am going to order an FSM today to start there. Hopefully that will lead me to some answers quickly... the easy kind!!

Another question, I briefly read some thread in my searches about converting it to a manually shifted 4wd system rather than whats is there now. Have you done that on any cruisers and how hard is it to do the change and locate all needed parts?

04-16-2008, 02:25 PM
Played around some with it and am alot more familiar with what i am looking at now from my research. The revving to get the vaccum up didnt seem to help get it engaged. I ordered a FSM from Toyota this week so I will dive into it a bit once i get that. I did run into something interesting. When I drove it to the shop(2 seconds from my house) the 4wd would not disengage and hubs were not locked but there was a grinding sound almost as if the gears/axle in front were turning but driveshaft wasnt. Kind of an uncomfortable noise. I left it at the mechanic for a little investigation and to get the brakes bled and oil changed and jogged home.

04-16-2008, 04:04 PM
I suspect (but don't know) that the system used manifold vacuum, rather than ported vacuum. Revving the engine (in this case) will lower the vacuum that the xfer case shifter sees.

In addition to a vacuum pump, you need a simple vacuum gauge so that you can see what the transfer case shifter is 'seeing' as far as vacuum. The FSM should clear up the entire vacuum picture for you. Just be aware of the two kinds of vacuum that exist on vehicles - manifold is high at idle (15"+) and ported vacuum is high at high RPMs.