Adjusting the spring on an FG cab lift mechanism

[kerry]

This discussion began in my cargo rack thread but I thought the instructions were worth a thread of their own. The effort it takes to tilt the cab on an FG is determined by the load on a spring(?) or torsion bar(?) at the front right side of the cab. There is a bolt into the side of the 'can' holding the mechanism in position, an adjusting bolt with a lock nut which pushes against an 'ear' on the spring mechanism. These are accessible with the cab tilted over the top of the AC condensor mechanism.

Bolt into the side of the can 14mm
Adjusting bolt--17mm
Lock nut--22mm

First loosen the lock nut a little bit. Then back out the adjusting bolt quite a way. Then put a wrench on the lock nut to hold it in place and turn in the adjusting bolt the number of turns you think it needs to be adjusted.(it will not be hitting the ear at this point) I did mine about 6 threads or so since mine was hard to lift even without a roof rack. I suspect it had never been adjusted since new.
Then, turn the adjusting bolt back into the mechanism until it hits the ear. Then loosen the bolt in the side of the can that holds the spring in position. Then tighten in the adjusting bolt. It should snug up against the lock nut which you had moved to its new position. Finally tighten the bolt in the side of the can to hold the spring in position.
Test your work.
Should take about 20 minutes.

 

[whatcharterboat]

Well done Kerry here is the pic from that thread. Glad you sorted it out.

 

[kerry]

Thanks for bringing that picture over. For future reference, I believe the picture is from a right hand drive FG which has the adjustment on the left side of the truck(?) Left hand drives have the adjustment on the right side.

 

[DontPanic42]

Thanks guys for the detailed instructions and picture. Now all I have to do is get my dead butt in gear and get the job done.
Bruce

 

[skijunkie]

The instructions are great but it appears the added picture is now a dead link. I need to adjust my cab tilt as it is pretty difficult to raise. I can easily locate the adjusting bolt and the lock nut but I am not sure about the side bolt.

I'm attaching a couple of pictures from the service manual. It is surprisingly sparse on details. It only mentions the adjustment bolt and doesn't mention which direction to turn the bolt. From this post i gather that the further you screw in the adjustment bolt the easier it should be to tilt the cab up (correct me if I am wrong).

Can anyone point out the side bolt in these service manual pics? Or maybe someone has a different picture of the side bolt?

 

[SkiFreak]

The side bolt is pretty obvious to see; it's the one over the top of the slot. All it does is lock the spline to the spring mechanism.
Make sure you loosen this bolt before you try to adjust the tension. You should also have the cab tilted to do the adjustment.
If you run out of room in the slot before you get the desired tension you will need to reposition the spline. To do that, simply back off the adjusting bolt completely and then remove the side bolt. With the side bolt removed you can easily slide the adjuster off. When you have done that, index it clockwise one spline, replace the side bolt (but do not tighten it) and screw in the adjusting bolt again. When you get the desired tension for the cab lift, tighten up the side bolt. Easy peasy...

In addition...
Looking at your first image, the side bolt is just above the top left corner of your little red rectangle. If you look closely you will also see the slot I mentioned.
Also, if your adjuster is on the right hand side of the truck, you would need to rotate the adjuster counter-clockwise to index the spline. On a right hand drive truck the adjuster is on the other side.
(Kerry did mention that, but I did not read his post before replying)

 

[Czechsix]

Yep, much easier to tilt the cab first. I wonder if it's the same mechanism through all the years?

 

[GR8ADV]

The side bolt is pretty obvious to see; it's the one over the top of the slot. All it does is lock the spline to the spring mechanism.
Make sure you loosen this bolt before you try to adjust the tension. You should also have the cab tilted to do the adjustment.
If you run out of room in the slot before you get the desired tension you will need to reposition the spline. To do that, simply back off the adjusting bolt completely and then remove the side bolt. With the side bolt removed you can easily slide the adjuster off. When you have done that, index it clockwise one spline, replace the side bolt (but do not tighten it) and screw in the adjusting bolt again. When you get the desired tension for the cab lift, tighten up the side bolt. Easy peasy...

In addition...
Looking at your first image, the side bolt is just above the top left corner of your little red rectangle. If you look closely you will also see the slot I mentioned.
Also, if your adjuster is on the right hand side of the truck, you would need to rotate the adjuster counter-clockwise to index the spline. On a right hand drive truck the adjuster is on the other side.
(Kerry did mention that, but I did not read his post before replying)

Anybody have actual pictures? I would love to reduce the effort to lift. Thanks.

 

[SkiFreak]

Anybody have actual pictures? I would love to reduce the effort to lift. Thanks.

Bolt A and Locknut A together make up the tension adjuster.
Bolt B is the "side nut" and is used to secure the adjustment sleeve.

With the cab tilted, undo Locknut A and loosen bolt B, then screw Bolt A in to make lifting the cab easier.
If you run out of thread on Bolt A and the cab is still heavy to lift, back off Bolt A to the start of the thread and then remove Bolt B. You can then slide the adjustment sleeve off the spline. Index it one spline, replace Bolt B (do not tighten) then try screwing in Bolt A again. When the desired lift force is attained, tighten Locknut A and Bolt B. You're done!

Other than coming and doing the adjustment for you, that's about as simple as I can make it.

 

[Larrylandcruiser]

Love your work - made a hard job easy for us technically challenged - cheers

 

[whatcharterboat]

Hi . The only info I can add is that if you apply too much tension (and this depends entirely on the cab weight) then you will have trouble lowering the cab. Once a standard cab is fully raised there is virtually no load on the torsion bar and it is easy for one person to pull that first bit. ..... But too much tension(while it will help at the start) can be extremely hard to pull that first few hundred millimetres.

Also if you do decide that there isn't enough adjustment and rotating the adjuster one spline is your answer ( not a FUSO answer I'm sure) then you may need a bit of leverage to line things up. You'll know what I mean when you do it. A couple I've done were a bit tricky ..... Almost like one spline the was a bit too much.

I've also extended the slot in the adjuster just a little bit too which worked very well on a really heavy cab.

regards John

 

[westyss]

View attachment 328222

Bolt A and Locknut A together make up the tension adjuster.
Bolt B is the "side nut" and is used to secure the adjustment sleeve.

With the cab tilted, undo Locknut A and screw Bolt B in to make lifting the cab easier.
If you run out of thread on Bolt A and the cab is still heavy to lift, back off Bolt A to the start of the thread and then remove Bolt B. You can then slide the adjustment sleeve off the spline. Index it one spline, replace Bolt B (do not tighten) then try screwing in Bolt A again. When the desired lift force is attained, tighten Locknut A and Bolt B. You're done!

Other than coming and doing the adjustment for you, that's about as simple as I can make it.

Sorry Owen but I dont get it? It looks like bolt B needs to be loosened before screwing bolt A in no? See maybe you need to actually come over and do it for me! It looks as though bolt B is similar to an alternator's set bolt but I might be looking at it wrong?? Logically looking at it I would say we need to screw bolt A in and not bolt B. Is that correct?

 

[SkiFreak]

It looks like bolt B needs to be loosened before screwing bolt A in no?

That is correct.
Sorry, I see that I failed to mention that.

See maybe you need to actually come over and do it for me!

No problems. When can I expect the plane tickets?

Logically looking at it I would say we need to screw bolt A in and not bolt B. Is that correct?

Too many drugs, obviously... You're right.

Bottom line... It's not a difficult task and when done can make a significant difference in the amount of effort required to lift the cab.

 

[westyss]

Owen, thanks for posting the image and explanation, makes sense now. Had me wondering there.

 

[pugslyyy]

Bottom line... It's not a difficult task and when done can make a significant difference in the amount of effort required to lift the cab.

I' going to have to look at this - my cab is heavy, and for some reason it never even occurred to me to check to see if the lift assist could be adjusted. Thanks.