F75 Rocky Gearbox/Transfer Overhaul

[tabrocky]

Hi all,

Just getting ready to do a complete strip and rebuild of the gearbox and transfer case in my '92 tdi rocky.

Just wanted to know if anyone is interested in photo's, etc of the insides of the box for reference? Or if people just want to follow the rebuild?
I know many people on here have already played with these things so there may not be much interest.

If I get a few interested people i'll take photo's and post them up as I go.

Have done the same thing to my '86 rocky back a couple years ago so not expecting any dramas. It's not a hard job with the right tools, some time and a bit of knowledge.

The rebuild is not because I have a problem, more so preventative maintenance while I have access to the tools and I know it will need it in the not to distant future.

After the overhaul is done I will be giving the truck a 2" suspension lift, new 31" tyres, new 2.5" exhaust and stainless snorkel.


Cheers

[dai-hard]

Im sure ill need to do mine sooner or later.
Ive done a 4spd in a f20 a long time ago
So any pics would be cool.

[Newtothefourbeworld]

i am interested in pictures.....


the gearbox is one shadey area of knowledge for me but im sure mine will need doing soon as its up to 250000kms and just about to be used for offroading for the first time

[Buggerific]

Very keen for phot's and I will be follong the project.

I just had to take out my gearbox because of my own stupidity but hardly had to open it so some pictures would be good for that. I'm also keen to see the easiest way to get the box in and out. I'm sure we did it the hardest way!

[HotFourOk]

Yeah, Pics would be great!

Mine's got a bit of a whine at the moment, and may need the bearings done in the not too distant future.

[mrRocky]

i paid some jackass $2500 to rebuild mine cause it was noisy, got it back and it was worse. i think he tried to get away with reusing the old
bearings. what a jackass. thanks topgear gearbox repairs
located on lord street beechboro if anyone else wants a shit job for lotsa cash

[tabrocky]

Right'o

Well it took a bit of time to get around to putting these photo's up but i've finally done it.

Here's the progress so far.

Box out and on the floor:
No real tricks to this.
Jack the vehicle up and place on stands or the like. Make sure it cant fall!!!
Remove both gear leavers. The stuby lever is removed complete with its mount to the transfer case. Thats why it has a rubber gasket.
Remove the drive shafts.
Crack all the bell housing bolts and gerabox cross member bolts first.
The top bell housing bolts can be a real pain to get at. The best way I've found to do these is using another spanner threaded onto the 17mm spanner to act as an extension. Hard to explain but it works. Dont use cheap tools otherwise they'll break.
Once everythings loose, take out all bolts, bar two lower bell hosing bolts and 4 cross member bolts.
Place a trolly jack under the centre of the cross member and jack it up to take the load, then undo the remaining bell housing bolts.
Lower the jack slightly so the whole engine and gearbox tilts back further.
Place a block of wood between the back of the engine head and the firewall to stop the engine falling backwards once the gearbox is free.
Remove the two remaining bell housing bolts and roll the gearbox free on the jack.
Lower the jack as far as it will go.
Its a good idea to have a few blocks of wood and a couple small squares of plywood to be able to sit the gearbox on once free. This prevents dents and damage the housing and the concrete floor.
Jack one side of the vehicle up further so the gearbox can be slid out on the plywood.

[tabrocky]

This is the new clutch from Adelaide Clutch Services (ACS).

It's there Heavy Duty Xtreme Outback Clutch and pressure plate kit KDA24002HD.

The guys there are excellent. Fantastic service and advice. I highly recommend them to anyone who's in need of a clutch for basically anything.

For $500 I got the works including clutch disc, pressure plate (~50% increase in clamp load on standard), thrust bearing, spigot bearing, flywheel machining, new dowels in the flywheel AND they even threw in an ARB E-Z deflator as part of a promo they've got going till the end of Dec.

Awsome. What more can I say.

They also make "Clutch-Pro" brand clutches like the one RockyF70 used in his.

The clutch had already been replaced once before with a Daikin / Excedy unit. This seemed to have a rattle that was apparently a common problem due to the very positive firing stroke of the diesel. I think they have fixed this issue now however.



This is my SST (special service tool ) for removing the spigot bearing. You can only use it when the flywheel is on. Basically you slip the ground bolt head into the bearing then slip the two metal tags in. Then its just a matter of doing up the nut on the thread. The plate presses against the flywheel bolts. The photo shows how it looks when the bearing pops out.

[tabrocky]

The fun begins:

Remove transfer case rear cover.
Drill out the lock nut dents on all lock nuts using a 5mm drill bit or similar. I've tried other ways to get these buggers off but this is the least brutle and easiest way i've found. Dont drill so far as to drill into the shaft. A little bit doesn't matter tho'. The idea is to thin out the metal in the dent so that when you turn the nut it just chews out the remainder by itself.

Undo the nuts with a good quality socket. You may need to use a bar extension to get enough leverage. These nuts are done up tight and need to be. If you do use an extension make sure your tools are up to it. If not find another method to do it.
I also drilled a couple holes in a piece of angle iron to bolt up to the output shaft coupling so that I had something to push against.

Also make sure the transfer case selector is in the high-range position

Note that if you can lock the gearbox up by engaging a gear (prefereable 4th) and reverse at the same time. The reverse slide gear will actually drop in by itself due to gravity if the gearbox is sitting upright on the bell housing. This helps to when undoing those nuts.

I also recommend wearing riggers gloves and sefety glasses when undoing these nuts incase something lets go in a hurry and you belt your hand into something or a tool shatters....
Yes, yes my gloves are on the floor but I took them off to use the camera.

[tabrocky]

Once your at this stage shown below your ready to remove the casing.



To reveal this:





From here on everything just about falls apart. Make sure as you slide parts off the shafts you place them in order on a bench / table to make things easier when you come to re-assemble everything.

[tabrocky]

Ever wondered why you cant get crawler gears for a rocky transfer case?

Answer: They don't fit!

This photo shows the low-range gear and how close it comes to the selector rod mounting in the lower casting. There's about a 3mm gap.

[tabrocky]

Once the transfer case gears have been removed it should look like this:



Now your ready to split the transfer case from the gearbox. Doing this reveals the overdrive (5th gear) hanging out the back of the gearbox.
A rubber mallet comes in handy when trying to break gasket seals. A few gentle taps and vola!

[tabrocky]

This is how the bench looks. All parts spread out in relative order.



This is as far as i've got at this stage.

No rush as some of the parts I need are on a slow boat from japan....

[tabrocky]

While I've got the starter motor out i'm also going to give that a service too.

Bearings and contacts.

The photo below shows the bits for the solenoid to suit the 2.2kW Denso starter (used on later F75's and F78's I suspect)

The older rockys use a 2.5kW Denso unit which is different.

One way to tell the difference is the sound the starter makes when cranking. The 2.5kw unit makes a sound more like that of an old 60 series crusier diesel cranking.
Where as the 2.2kw unit has a higher pitch sound which is similar to that of a current model prado or hilux diesel.

[dai-hard]

Way to go
Does anyone know if a petrol (f80) transfer is the same and what ratios are they.
I want my hi range to be 1:1 instead of 1:1.297

cheers craig.

[philme4567]

mmm looks like something similar to what i am in the middle of doing right now. All the bearings were stuffed and the seals between the gearbox and the transfer, what an expensive episode it is tho.

[tabrocky]

Yeah certainly not a cheap job.

I guess im doing it the "premium" way using all genuine parts (excluding the clutch). Having said that tho' I priced a couple of the bearings at CBC and they came back substantially more expensive than genuine. But then again when ur spending around $1100 in spare parts at the one place you usually get a better deal.

Another reason I'm using genuine bearings is because they tend to be made in japan, where as the bearings from general bearing shops often tend to be malaysian or the like and don't have the exact same part numbers. The part number differences can indicate different operating temperature ranges / expansion coefficents which, despite seeming insignificant on the surface, can lead to premature failure if used in the wrong application.
Your often left at the mersey of the person behind the counter to make the correct substitution / decision.

Pricing so far:

Bearings, gaskets, seals, x2 uni joints (rear prop shaft) and clutch cable = $1100

Clutch = $500

Starter Motor bearings, contacts = $50

All up I guesstimate around the $1700 mark allowing for a bit of extra.

[tabrocky]

Also one other thing i've noticed from previously doing a similar rebuild on my earlier model ('86) diesel rocky, is that some of the bearings are different.

I hope to note the differences if people want to know.

Cheers

[philme4567]

Im interested to now where you are getting your bearing prices Ta Brocky, The prices im getting at CBC are out of this world, $50 plus tax for one bearing.

[tabrocky]

CMI Toyota. Wright st in the city.

A couple of the larger bearings have hit the $100 mark but most are around the $20 mark.

I would suggest that you replace ALL bearings while your in there. I did all bar 1 last time... And guess which one died 50,000 ks later...

It was the bearing on the Hi/Lo idler gear in the transfer case which has itself pushed hard up against the smaller gear and has the exact same outer diameter as the gear. This makes it impossiple to get anything behind it to pull it off. A mate of mine did the box in his rocky and tried getting a chisel in behind it. Ended up chipping a tooth off the gear....

Best way to get it off is with the angle grinder. Cut the outer off and take out all ball bearings, leaving only the centre on the shaft.
Then grind two flats on opposite sides of the inner bearing case remaining, almost until you get down to the shaft. Then using a cold chisel, split the inner bearing case at the thinnest points.
This should see the bearing off with no damage to the gear.

Just another point. This bearing is a ball race type in older rockys, but in the newer one im doing now on my turbo box its a roller bearing. Possibly to handle the extra power the turbo motor has. Might be worth up-grading while your replacing yours. However I expect it would be a more expensive bearing.
If you want the part number off the bearing let me know.

Good luck.

Cheers

[tabrocky]

Well after moving states I've finally had the chance to update things a bit.

The gearbox is in and runs smoother than ever. Whisper quiet now.
No real issues with the assembly. Every thing went back together piece by piece as expected. Clutch operation is smooth and suprisingly light.

Total costs were:

Factory Parts (all bearings, needle bearings, seals, gaskets, shift boots) = $1110

Uni joints x2 = $99

Clutch cable = forgot?? about $100

Starter motor solenoid overhaul kit = $35

Starter motor bearings = $40

HD Clutch and bearings = $500

TOTAL = $1884


Also fitted a new exhaust system. 2 1/2 inch straight from the turbo. I used three 12" long hotdogs and a flexible bellow after the gearbox mount. Made it up as 3 seperate pieces so it just bolts all together and routed it more down the centre of the vehicle so ive got room for a water tank underneath.

Not noisey at all which is what I wanted. Has a much deeper note and the turbo is a bit more audible. Sounds great!!!
Exhaust gas temps also went down along with the engine temps especially working hard up hills.

Finally I also fitted my 2" lifted lovells springs off my other rocky which makes it handle a heap better on the road.

Just before I put it on the truck to have it shipped interstate I took it to get dyno tuned. They were able to turn the fuel up a tiny bit as the new exhaust had leaned out the mixtures making it run super clean. I had it set for the optimum fuel ratio (not max power) for reliability and longevity sake.
Max power at this setting was 58kW at the rear wheels. 3600rpm on the tacho.

This works out to be 82kW at the flywheel assuming 30% drive line losses.

Might not be much in todays terms but im happy...

Will post the last few photos of the box plus some of the exhaust, suspension and dyno plot soon.

Cheers.

[boofed]

heh guys,

new to the game, but my recently acquired rocky...long story...is having a shit of a time staying in high range....it popped out in a very awkward situation and we where stuck for quite a long time resulting in near divorce before i was even married....still too the day it has done it but now we know how to rectify by removing the 4x4 gear shifter and manually locking it back in with a screw driver...low range is fine will pull a two tonne trailer up a very steep hill on the bloomfield track with no hassle but high range it seems under load to "pop out"...is the only way to solve this to crack the transfer case again...anybody else had this prob????

[dai-hard]

Mine did that when i 1st got it.

It was the vacum solinoed on the transfer.

[RockyF75]

What does it pop into from High range? Does it just pop out of gear? or does the transfer lever pop into neutral?

[dai-hard]

yer they jump out of hi- into neutral.

The stupid PSS(dumbass vacum shift ) has a vacum operated piston to move from 2wd to 4wd. Mine had a broken vacum switch.
Hasnt done it since i changed the switch and im running twice the HP then the diesel

[RockyF75]

Mine doesn't have any vacuum operated stuff but I've had similar happen twice to me and once on a mates rocky ute. Takes about 30mins to pop back in but its a PITA to get your hands around near the right bolts. Mine also jumps out of 1st gear into neutral when engine braking down steep slopes

[tabrocky]

If yours has a "4H" button on the dash then it uses a vaccum solenoid to engage 4wd. This solenoid works completley independently of the HI-LO selector. Im not quite sure how problems with the solenoid can effect it jumping into neutral? Doesnt make sense. You can see in the photos that there not connected.

Older rockys that have 4H on the lever have interconnection inside the transfer between the HI-LO and 4WD selectors. This may cause some issues. Cant say I've ever had a problem with mine like that.

If the lever is very easy to operate and there is no decernable feel between the positions then the detent ball bearing and spring maybe missing or broken.

Thats about all I can tell you.
Like I said, I havent experienced this problem with either of my rockys before. Be interested to find out what caused it.

Good luck.

Cheers

[dai-hard]

Im only guessing. But the vac/switch on mine that was broken was the one that applies vacum to hold it in 2wd and when i fixed it, it didnt do it again.

The detend on the shift lever feels good and after looking at the pics i couldnt work how they were conected.

And mine never jammed up would just go back in.

It can be scary i was doin 100kph up a hill with B-double up my arse and got a box full of neutrals.