Pedal box can be a curse but once you know where all the sneaky hidden bolts are ti is quite straightforward. Clutch master and slave easy enough to get or you can go cable clutch. Most gearboxes have the front cover drilled for either push or pull arrangement. I got a couple of cables if thats the way you want to go. I have a pedal box and other useful bits as well and i know where another one is so none of that is a problem. Other issues are tthe gearbox mount and prop shaft. Some of ther turbo auots have a different box support member but it is quite easy to modify. The hole in the tunnel usually needs opening out a bit as well but not a huge amount. Prop shaft length is different so bear that in mind if you track down a box get the shaft that goes with it. A wiring loop needs to be added to the connector on top of the tunnel to complete the old auto safety start circuit otherwise you will wonder why it won't turn over. You also need to pluck the centring bush out of the end of the crank and replace it with a spigot bearing, 6203zz or 6203rs from memory, doesn't matter which. can be standard or c3 clearance.
A few of us have done it so no drama getting info and support.
rodeo and gemini gearboxes
Splines, Yokes & Driveshafts (Isuzu)
Just a quickie on shafts & splines...
It seems you can get any combination of replaceable driveshafts & splines.
This is based mainly on the older, smaller, universal joints (UJs) with external clips, but may also hold true for larger internal clips UJs.
The following info is off my head (as I am) and may need checking... were are those scribblings..?
I categorise 3 types of UJ types - the permanent irreplaceable types; the early external clip UJs (as found on all older Belletts, Florians, Wasps, and many Geminis, KB-Rodeos, Jackaroos and Piazzas); and the later large UJs with internal clips (found on later Isuzu models). Ignoring the permanents, that means the 2 replaceable types (small & big).
There are 2 splines (older course & newer fine) and 2 (or 3?) yoke diameters with two flange sizes (older small as per all "passenger" Isuzus, and later large as on later Jackaroos (eg 2.6L 4ZE1 from 1989) & Rodeos).
Course splines (gearbox output and clutch plate) exist on older Isuzus - eg, 117s, early Geminis, Rodeos etc.
Later boxes changed to fine splines, but some have a course clutch & fine output shaft combination (eg - several 117 gearboxes).
All the above were the smaller diameter yoke.
The yokes then went to the larger diameter, for autos, then for Rodeos & Jackaroos (and Geminis & Piazzas?).
There exists a version of each yoke with the small UJs.
Most shafts come with small UJ variants. EG - I have 2 Piazzas, one has large non-replaceable UJs, the other has the small UJs.
Many shafts have similar section or overall lenghts. EG - Florian is same length as Piazza (but it's one-piece), and various Jackeroo/Rodeo sections match those of Piazzas etc (to within 5mm).
The point is, if you have enough Isuzu shafts to chose from, you'll probably be able to get any required length etc.
It's worth collecting yokes. I started with small fine-splines to put ZZ/R etc boxes into my Belletts & Florians.
The big fine-spline yokes come in both UJ variants (strange having a small UJ for a big spline?). (I got one of each recently from Pick-A-Part from 1987 & 1990 Jackeroos.
I'll be seeing if there are small splines with big UJs, and big flanges with small UJs - that means virtally any combination of early/late gearbox/diff can be mated.
And I'm developing an interest in the big UJs - these may be better wearing (and stronger!) than the smalls. I'm imagining the later larger Rodeo & Jackaroo diffs behind torquey twincams...!
It seems you can get any combination of replaceable driveshafts & splines.
This is based mainly on the older, smaller, universal joints (UJs) with external clips, but may also hold true for larger internal clips UJs.
The following info is off my head (as I am) and may need checking... were are those scribblings..?
I categorise 3 types of UJ types - the permanent irreplaceable types; the early external clip UJs (as found on all older Belletts, Florians, Wasps, and many Geminis, KB-Rodeos, Jackaroos and Piazzas); and the later large UJs with internal clips (found on later Isuzu models). Ignoring the permanents, that means the 2 replaceable types (small & big).
There are 2 splines (older course & newer fine) and 2 (or 3?) yoke diameters with two flange sizes (older small as per all "passenger" Isuzus, and later large as on later Jackaroos (eg 2.6L 4ZE1 from 1989) & Rodeos).
Course splines (gearbox output and clutch plate) exist on older Isuzus - eg, 117s, early Geminis, Rodeos etc.
Later boxes changed to fine splines, but some have a course clutch & fine output shaft combination (eg - several 117 gearboxes).
All the above were the smaller diameter yoke.
The yokes then went to the larger diameter, for autos, then for Rodeos & Jackaroos (and Geminis & Piazzas?).
There exists a version of each yoke with the small UJs.
Most shafts come with small UJ variants. EG - I have 2 Piazzas, one has large non-replaceable UJs, the other has the small UJs.
Many shafts have similar section or overall lenghts. EG - Florian is same length as Piazza (but it's one-piece), and various Jackeroo/Rodeo sections match those of Piazzas etc (to within 5mm).
The point is, if you have enough Isuzu shafts to chose from, you'll probably be able to get any required length etc.
It's worth collecting yokes. I started with small fine-splines to put ZZ/R etc boxes into my Belletts & Florians.
The big fine-spline yokes come in both UJ variants (strange having a small UJ for a big spline?). (I got one of each recently from Pick-A-Part from 1987 & 1990 Jackeroos.
I'll be seeing if there are small splines with big UJs, and big flanges with small UJs - that means virtally any combination of early/late gearbox/diff can be mated.
And I'm developing an interest in the big UJs - these may be better wearing (and stronger!) than the smalls. I'm imagining the later larger Rodeo & Jackaroo diffs behind torquey twincams...!
IZU069 - ISUZU means a lot to me.
The so called non replaceable UJ's are infact replaceable with a bit of imagination, i used to do it years ago for Ford (escorts, Cortinas) and Renault R13 thro R16 etc.
It involves pressing out the staked joint, skimming out the yoke bores to the next standard size which from memory was 22mm. Then you can re stake them but I preferred cutting circlip groves where the yoke had enough meat to take it. On some you couldn't so staking was the only option. For a few years there were some cowboys on the job and they used to weld washers on the outside to keep them in..NASTY and not very professional.
The point is that they can be repaired with basic engineering. I remember we were doing them for about $80.00/journal including the re-greasable UJ which was good at the time when a complete new shaft was over $400 and the bonus was they were replaceable as normal later if required.
It involves pressing out the staked joint, skimming out the yoke bores to the next standard size which from memory was 22mm. Then you can re stake them but I preferred cutting circlip groves where the yoke had enough meat to take it. On some you couldn't so staking was the only option. For a few years there were some cowboys on the job and they used to weld washers on the outside to keep them in..NASTY and not very professional.
The point is that they can be repaired with basic engineering. I remember we were doing them for about $80.00/journal including the re-greasable UJ which was good at the time when a complete new shaft was over $400 and the bonus was they were replaceable as normal later if required.
So many cars, so little cash
Aha! - not backyard replaceable.
But good to hear the "irreplaceables" have been replaced - NICE to know. There is always a way!
I'd prefer the machining for the circlip too - once done, always replaceable.
As to welding, I think I'd prefer worn UJs - and they're dangerous enough.
(Why do people like to heat or weld key components like axles, yokes, stub axles, springs...? Is it just for my entertainment, or do others like the bangs and ker-chinks that often follow?)
I forget too that shafts can be cut & joined - that used to be an expensive option, but prices seem reasonable these days.
But good to hear the "irreplaceables" have been replaced - NICE to know. There is always a way!
I'd prefer the machining for the circlip too - once done, always replaceable.
As to welding, I think I'd prefer worn UJs - and they're dangerous enough.
(Why do people like to heat or weld key components like axles, yokes, stub axles, springs...? Is it just for my entertainment, or do others like the bangs and ker-chinks that often follow?)
I forget too that shafts can be cut & joined - that used to be an expensive option, but prices seem reasonable these days.
IZU069 - ISUZU means a lot to me.
It is because they were dropped on their scones when they were little, their sum total toolkit is a half brick and a cold chisel, which is handy for fixing the Harley they often ride very badly....biased? Me? Nah(Why do people like to heat or weld key components like axles, yokes, stub axles, springs...?
So many cars, so little cash
Thanks Wedgy & Bugle,
I like scones but I get a bit sick of those dented or bruised ones. LOL
I too think Commodore "big-fine" splines fit - RodeoBob has said something similar.
One day I'll count & measure my splines. All I remember is 1" 10-tooth (course) for early clutch plates. And diff centres for all EXCEPT Aussie Gemini and later "big-diff" Isuzus are the same spline, but 1", fine spline...?
Another 10-minute job pending.....
PS - I know of a non-Victorian Bellett Racer that kept blowing the traditional small (1" OD) external-clipped Uni-Js so he converted to "Ford Taxi" UJs (this was more than 10-15 years ago, and he had access to milling machines etc).
I like scones but I get a bit sick of those dented or bruised ones. LOL
I too think Commodore "big-fine" splines fit - RodeoBob has said something similar.
One day I'll count & measure my splines. All I remember is 1" 10-tooth (course) for early clutch plates. And diff centres for all EXCEPT Aussie Gemini and later "big-diff" Isuzus are the same spline, but 1", fine spline...?
Another 10-minute job pending.....
PS - I know of a non-Victorian Bellett Racer that kept blowing the traditional small (1" OD) external-clipped Uni-Js so he converted to "Ford Taxi" UJs (this was more than 10-15 years ago, and he had access to milling machines etc).
IZU069 - ISUZU means a lot to me.
G'dam it Bugle - you You-You! No-one upsets my round-tuit schedule! Grrr!
Before I get to the ahead-of-schedule measurements that I just obtained from my cold, dark shed.....
Yep - I reckon Piazza diffs would be compatible with the early Rodeos & Jackaroos (ie - 1984 to ~1988); their banjos are interchangeable - see later (wanna 4.55:1 Piazza?).
Early gearboxes had course ins & outs. These were typically one-piece boxes - you could not separate the front&bell housing from the rear (ie, no central gear carrier plate; I'm not talking about the very-rear "extension" housing).
They then went fine-spline input (clutch) with course out (eg some 117 boxes; I think still all 1 piece).
And finally fine/fine spline.
At some stage the flywheel 6203 bearing went from 16mm to 17mm ID (the 6303 has 5/8", 16mm & 17mm ID versions!) - maybe this was pre- or else early-Gemini?.
I'm certain I have seen early Gemini one-piece gearboxes, and I think with course spline or splines. Ditto for KB (early Rodeos).
Diff flanges were similar - early course and later fine spline.
And later again, they beefed up the shaft diameters (all fine splines) for gearboxes & diffs (eg - bigger UBS17 Jackaroo & TFR Rodeo gearboxes & diffs; from ~1989?).
I remember something about Bellett differential half-shaft splines being the same as other splines on the Bellett (diff-yoke? clutch?) but I know the GT-R Belletts had larger half-shafts (I'd assume with larger diff-yokes).
An example of interchangeability I know of:
Differential - the entire banjo/carrier can be interchanged between Florian, Wasp, Piazzas and early Rodeo/Jackaroo (till 1987 or 89?); the axle splines are all the same.
And whilst some diff parts are interchangeable (eg 4.1:1 Florian crown&pinion with Bellett 3.1 & 3.9:1), for others it depends on the bolt pattern (ie old 8-bolt, Piazza/Rodeo/Jack 10 bolt, and post-89 Rodeo/Jack 12?-bolt?).
Alas Aussie Geminis have a Salisbury diff.
Gearboxes - hmmm.
Place a 5-speed box behind Wasp and use a standard Florian drive-shaft (maybe with fine-spline gearbox yoke).
Others are usually a case of RHS vs LHS starters and matching in/out splines.
Most bellhousings are similar though some bolts may be slightly different.
Later TFR/UBS17 gearboxes look the same as earlier, but are longer and I think have bigger bellhousings.
To convert RHS starter Gemini box to LHS starter ZZ/R or twincam box - change the bell housing, maybe change layshaft ball/needle bearing, and maybe change the clutch throw-out lever and re-mount.
Diffs - hmmm!
I think generally 2 sizes for the flange face (4 bolts) with the larger flange starting with UBS17 & TFR.
But there are a few flange "lengths" and at least a course (10t?) & fine spline (small & large).
Some RECENT spline measurements noting that these are approximate and teeth may be miscounted!
- early course-spline clutch - 1" x 10t (diameter x teeth).
- common fine-spline clutch - 1" x 24t
- early UniJoints - 15/16" (~23.5mm) OD (external circlips).
- later UniJoints - 1-1/8" (~29mm) OD (internal circlips).
- early prop-shaft/gearbox yokes - 1-3/8" (34.9mm) OD; 18t (10t if course)
- larger prop-shaft/gearbox yokes - 1.5" (38.1mm) OD; 27t
Diff axle shafts - ~27mm x 17t (or bigger UNS17/TFR etc ~34mm x 26t).
I presume it's the 1.5" x 27t shaft-yoke with 1-1/8" UJs that's the same as Crappadore etc?
Now I'll probably spend my "next time" finding and measuring all the above combinations.
That's cool - another excuse to RodeoBob for NOT getting the Jackaroo on the road (I'm so sick of procrastination - I need other excuses!)
Thanks for getting my by off this seat!
Before I get to the ahead-of-schedule measurements that I just obtained from my cold, dark shed.....
Yep - I reckon Piazza diffs would be compatible with the early Rodeos & Jackaroos (ie - 1984 to ~1988); their banjos are interchangeable - see later (wanna 4.55:1 Piazza?).
Early gearboxes had course ins & outs. These were typically one-piece boxes - you could not separate the front&bell housing from the rear (ie, no central gear carrier plate; I'm not talking about the very-rear "extension" housing).
They then went fine-spline input (clutch) with course out (eg some 117 boxes; I think still all 1 piece).
And finally fine/fine spline.
At some stage the flywheel 6203 bearing went from 16mm to 17mm ID (the 6303 has 5/8", 16mm & 17mm ID versions!) - maybe this was pre- or else early-Gemini?.
I'm certain I have seen early Gemini one-piece gearboxes, and I think with course spline or splines. Ditto for KB (early Rodeos).
Diff flanges were similar - early course and later fine spline.
And later again, they beefed up the shaft diameters (all fine splines) for gearboxes & diffs (eg - bigger UBS17 Jackaroo & TFR Rodeo gearboxes & diffs; from ~1989?).
I remember something about Bellett differential half-shaft splines being the same as other splines on the Bellett (diff-yoke? clutch?) but I know the GT-R Belletts had larger half-shafts (I'd assume with larger diff-yokes).
An example of interchangeability I know of:
Differential - the entire banjo/carrier can be interchanged between Florian, Wasp, Piazzas and early Rodeo/Jackaroo (till 1987 or 89?); the axle splines are all the same.
And whilst some diff parts are interchangeable (eg 4.1:1 Florian crown&pinion with Bellett 3.1 & 3.9:1), for others it depends on the bolt pattern (ie old 8-bolt, Piazza/Rodeo/Jack 10 bolt, and post-89 Rodeo/Jack 12?-bolt?).
Alas Aussie Geminis have a Salisbury diff.
Gearboxes - hmmm.
Place a 5-speed box behind Wasp and use a standard Florian drive-shaft (maybe with fine-spline gearbox yoke).
Others are usually a case of RHS vs LHS starters and matching in/out splines.
Most bellhousings are similar though some bolts may be slightly different.
Later TFR/UBS17 gearboxes look the same as earlier, but are longer and I think have bigger bellhousings.
To convert RHS starter Gemini box to LHS starter ZZ/R or twincam box - change the bell housing, maybe change layshaft ball/needle bearing, and maybe change the clutch throw-out lever and re-mount.
Diffs - hmmm!
I think generally 2 sizes for the flange face (4 bolts) with the larger flange starting with UBS17 & TFR.
But there are a few flange "lengths" and at least a course (10t?) & fine spline (small & large).
Some RECENT spline measurements noting that these are approximate and teeth may be miscounted!
- early course-spline clutch - 1" x 10t (diameter x teeth).
- common fine-spline clutch - 1" x 24t
- early UniJoints - 15/16" (~23.5mm) OD (external circlips).
- later UniJoints - 1-1/8" (~29mm) OD (internal circlips).
- early prop-shaft/gearbox yokes - 1-3/8" (34.9mm) OD; 18t (10t if course)
- larger prop-shaft/gearbox yokes - 1.5" (38.1mm) OD; 27t
Diff axle shafts - ~27mm x 17t (or bigger UNS17/TFR etc ~34mm x 26t).
I presume it's the 1.5" x 27t shaft-yoke with 1-1/8" UJs that's the same as Crappadore etc?
Now I'll probably spend my "next time" finding and measuring all the above combinations.
That's cool - another excuse to RodeoBob for NOT getting the Jackaroo on the road (I'm so sick of procrastination - I need other excuses!)
Thanks for getting my by off this seat!
IZU069 - ISUZU means a lot to me.