Isuzu gearbox and clutch bible.

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Rodeobob
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Isuzu gearbox and clutch bible.

Post by Rodeobob »

I got asked, so i thought i would make a thread in here about gearboxes etc so i dont get asked again. If i do, i can say tut tut you didnt search or look around.

Tonight i will do the short.
Ive updated some clutch data.


MSG
Everything except the 4ZE1 had an MSG type gearbox. 4ZB1-4ZD1 and G161Z-G200Z. (also C190 and C223 and G180W and G200W but with the starter motor on the opposite side).

Early had the coarse spline. Gemini and Rodeo.
Later had the Fine (1.8L 4ZB1 Shuttle too).

Vehicles fitted with the 4ZC1 and 4ZD1 had a large output shaft. (same as Trimatic etc.)

Clutch Activation
Cable clutch in the Gemini and Rodeo and hydraulic in the Shuttle and Piazza. There is two different provisions in the bellhousing for the different types of clutch actuation in most MSG boxes, there is a possiblitiy that you may have to swap over the front bearing carrier plate to enable the use of a clable clutch.


MUA
The Gearbox behind the 4ZE1 is called the MUA box. Its bigger and beefier (in the middle) but with the same bellhousing and overall length. It has the large output shaft the same as above.



Clutch Activation
Hydraulic clutch. This box was only in the 2WD (there was a 4x4 version) Rodeo. Hence it only needed a hydraulic clutch because thats what they had. Theres only provision for a hydraulic clutch in the bellhousing.


Clutch plates

(From Shuttle and Rodeo Factory manuals)
For the relavant diameter reguardless of motor the clutches will interchange.

Engine.....Size........Area..........Clamping force.

G161Z - 200mm A-181cm2......330kg Flat
G180Z
C190

G200Z - 215mm A-186cm2......350kg Flat
4ZB1 ....................................380kg
4ZC1 (Carby)........................380kg
4ZD1....................................486kg
C223....................................330/380kg
C223-T.................................486kg


4ZC1-T - 225mm A-221cm2....550kg Stepped flywheel
4JA1 (2.5L n/a Diesel)...........550kg Im unsure as to if this is a stepped flywheel.

4ZE1 - 240mm ?????............560kg Flat
4JB1-T (2.8L) -240mm.............640kg Im unsure as to if this is a stepped flywheel.

All clutches use the same centre drive spline on the clutch plate.
4Z motor have 8 bolts hold the flywheel on and the flywheels will inter-change to other 4Z motors.
G-series motors have 6 bolts hold the flywheel on and the flywheels will interchange to other G-series motors.


To convert the E1 MUA box to cable clutch.

You either need to convert the car to hydraulic mastercylinder and run a hose.

Or you need to make a mounting plate for inside the bellhousing to hold the piviot ball to make the cable fork work. If you do this you will need the engine to gearbox brace off a 4Z motor pre E1, this holds the gearbox end of the cable. They were all the same if my memory is right. Stick your nose under a Shuttle. If not a D1 Jackaroo/Rodeo is the same.



Or you could find a longer (clutch) cable from something else and run it in from the back of the car. That will mean the cable pulls the right way on the hydraulic fork. All you would need to do would be make some sort of holder to hold the cable to the side of the gearbox and some way of attaching the cable to the clutch fork.

Or you could make up a piviot that bolts to the side of the box that converts the cables pull into a push.


Its your conversion be creative and Good luck with it.


If youve got pictures post em up. Ive lost all my pics.

Cheers, Bob.
Piazza for sale, black, manual, in fair condition with heaps of parts $3500 (parts not for sale seperately)
DO NOT PRIVATE MESSAGE ME FOR ASSISTANCE, IM AN ASSHOLE YOU WILL GET AN EAR BASHING, ASK IN THE GENERAL FORUM.
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Rodeobob
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Post by Rodeobob »

Shifters

The MSG gearbox has a shifter mounting face that slopes toward the rear of the box.

The MUA gearbox has a shifter mounting face that it parallel to the main shaft in the gearbox.


The shifters are not interchangeable without modifications.
Piazza for sale, black, manual, in fair condition with heaps of parts $3500 (parts not for sale seperately)
DO NOT PRIVATE MESSAGE ME FOR ASSISTANCE, IM AN ASSHOLE YOU WILL GET AN EAR BASHING, ASK IN THE GENERAL FORUM.
tobytj
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Joined: Tue Apr 10, 2007 3:46 pm
Location: Brisbane

Re: Isuzu gearbox and clutch bible.

Post by tobytj »

Rather that start a new post this info probably sits well with bob's original work.

Image

When you go to buy a rebuild kit for a 5 speed (or 4 speed but why would you spend the money?) you are confronted with a choice of three kit options. All suppliers seem to use similar of the same kit ID codes.

K-ISU2025 - this is a kit for a 5 speed with a 4 bolt retainer on the input shaft (the bit that the clutch thrust bearing also slided along at the front of the gearbox). I am speculating thta this is becasue the layshaft front bearing is a needle bearing in these early boxes - happy for someone to confirm. I have never seen one of these gearboxes.

K-!SU2024 - this kit is for a 5 speed with a 6 bolt retainer that runs a fairly common 5205N bearing mid layshaft

K-ISU2025 - this kit is for a 5 speed with a 6 bolt retainer that runs a more specalised BD25-9 bearing mid layshaft. This is the only difference from a K-ISU2024

Image

The photo shows the BD25-9 fitted to a lay shaft and a 5205N (unmounted) beside it. The BD25-9 is a wider bearing and has more load capacity. To fit the extra width the reverse gear in a gearbox fitted with a BD25-9 is narrower. There is no difference in the layshaft itself.

To date all the gearboxes I have works on with a fine spline output shaft have had the BD25-9 fitted and the one course spline output shaft gearbox I have rebuilt had the 5205N fitted.

You can still fit a BD25-9 to replace the smaller 5205N and simply swap the reverse gear for a narrower one as they are a common sized gear. I have yet to remove a BD25-9 that is badly worn even when the rest of the bearings in the box are cactus.
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