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Discussion Starter · #1 ·
I changed out my 16" wheels on the 1990 NPR to 19.5's and looks like I have gained about 6 to 7 MPH with the taller tires. I am really happy with the Isuzu 5 speed and really don't think I need an overdrive transmission as all the shift speeds/RPM's with the 19.5" rims seem to work really nice on the hilly back roads here in the Ozarks I will be driving on. According to my GPS about 63 MPH is what I am getting, the old fat Diamond T front fenders ought to be happy about that speed.

I have been reading and researching my options for a top shifter for the original NPR 5 speed transmission and am coming up with not many options. Has anyone successfully changed the original NPR manual transmission convoluted shifter linkage to a top shifter?

If I am unable to keep the original shifter and need an adapter for a different transmission is there a reliable source for the adapters? I have a Ford small block ZF overdrive 5 speed and the Ford Cummins 4BT adapter/starter and flywheel. If someone has a recommendation for a reliable source for a transmission adapter and don't want to air dirty laundry please PM or e-mail me at brightwellrichard at Yahoo dot com (no spaces) I have read past posts that some have paid for adapters but not received them?????

I am going to start a build thread on my truck in a week or so, a '48 model 306 Diamond T. Still trying to figure out if I am going to put the Diamond T cab on the Isuzu NPR chassis or keep the Diamond T frame and put the 4BD1T engine/transmission and Isuzu axles under the Diamond T Frame. If I can overcome the steering gear/box relocation and the shifter issue I am leaning toward putting the Diamond T cab on the NPR chassis.

Any thoughts or advice appreciated.

Rick
 

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Since you are one of the few that doesn't need OD, I think you should stick with the entire NPR setup if possible. I say if possible since the NPR frame and axles are probably too wide for an old truck like that. Aren't they pretty narrow?
For the top shifter, do a search for the msa5 trans swap that someone did on AULRO (land rovers in australia). Oh yeah, Bush65 posted it here:
http://www.4btswaps.com/forum/showthread.php?16178-5-speed-question..&p=127818#post127818
I had forgotten, but they even will sell you a kit...
 

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Discussion Starter · #3 ·
THANKS!,
As for the width the rear doesn't really matter as I am putting a flatbed on the truck, the front Isuzu axle (outside tire to outside tire) is about 4" wider but I plan on adding about a 3" filler strip to the each of the front fenders to cover the wheels. The original Diamond T frame is a 34" frame so it should sit on the Isuzu chassis OK with fabricated cab mounts . I will have to move the fuel tank, battery box and the vacumn canister mounted on the NPR.

The reason I like the Isuzu chassis is the 6 bolt wheel big lug nut wheel looks very close to the original Budd truck type wheels on the Diamond T. My Diamond has the cast spoke type wheels but the Budd's were an option and I like them better than the cast spoke rims. I want 19.5 rims, to me 16" rims on a truck like the Diamond T don't look right. If I did not like the big lug nut look of the NPR wheels I could go with a 8 lug Dana rear and an IFS front. I looked into the 70's Dodge Motor home M Series Chassis that have a big 5 and 6 bolt Budd wheel but parts availability seems to be a problem with the 70's Dodge MH chassis. The 2 biggest problems I see using the NPR chassis are the steering and the shifter.

I have parked the NPR and the Diamond T with the front axles aligned and everything (radiators, top of transmission, front and rear of motors line up great. The whole swap will revolve around centering the front axle of the NPR frame in the diamond front fender wheel openings and everything looks like a go. If I was doing it over I would probably look for a Model 404 Diamond T and then I think the front axle width would be right on as the 404 truck cab is wider.....
 

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Discussion Starter · #4 ·
I have tried to contact the guy on the AULRO site who was making and selling the top shifter kit for the MSA5D transmission. After reading several post's there and trying to contact the fellow who was making them it's kind of looking like a dead end. The guy who was making the kit has not posted in a while, I sent him a personal message and it was returned "mailbox full"

Has anyone changed to a working top shift on the Isuzu MSA5D 5 speed? I have read about some have used a cable shift but have not had any luck contacting anyone who has actually made it work. Surely someone has done this?????

Thanks
Rick

I would really like to stick with the Isuzu 5 speed if I can overcome the shifting problem.

Rick
 

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Yeah the Aussie shifter kit never worked out for sale. A small batch was made and that was it.

There are basically three ways to make a different shifter work on a MSA gearbox.
1. Use a cable-change gear-lever from another car or truck.
2. Use a linkage arrangement to do the same job.
3. Graft a lever straight into the top of the box.

Mine has had #3 done, the concept was genius, the execution was awful. 20 years of wear later it's still usable but doesn't feel good. I plan to make a linkage arrangement to replace it in the future as I need to relocate the gear lever.
AncientMariner on AULRO made his own gear lever grafted into the top of the gearbox and it looks excellent. I'll try to find a picture later.

Bush65 did #1, he was using a 6sp Isuzu box (MXA-6) but the arrangement is similar.
The Aussie setup was #2, quite complex but seemed to work okay. The first few had a reverse lever throw which I personally wouldn't do.
 

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Ancient Mariner's gear-lever:

Top of the gear selector cut off to reveal the gates:


Finished Lever:



The sideways motion I believe is driven by a peg in the lever below the shaft. So from the rear pushing the lever left rotates the crank clockwise.
 

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there are all hydraulic shifters made for off road racing buggies---i saw a homemeade one on a corvette powered dune buggy where the corvette transaxle was used---the builder lives on table rock lake-shell knob mo...he runs the only fabricating shop there---there are only about 50 people that winter over there .....
 

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Discussion Starter · #8 ·
there are all hydraulic shifters made for off road racing buggies---i saw a homemeade one on a corvette powered dune buggy where the corvette transaxle was used---the builder lives on table rock lake-shell knob mo...he runs the only fabricating shop there---there are only about 50 people that winter over there .....
I am about 30 miles away from Shell Knob.
 

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Discussion Starter · #9 ·
Dougal,
Thanks for the pictures. I am studying the pictures of Ancient Mariners shifter.....at the rear looks like some kind of ball or knuckle under the vertical rod the shifter goes into? Do you have a link to the thread the pictures are from?

Thanks,
Rick
 

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Dougal,
Thanks for the pictures. I am studying the pictures of Ancient Mariners shifter.....at the rear looks like some kind of ball or knuckle under the vertical rod the shifter goes into? Do you have a link to the thread the pictures are from?

Thanks,
Rick
I don't have a link for the thread those pics came from. He had many threads over the years so it would take some finding. If you are registered on AULRO you could search by user name. It would take some time.

But yes the lever needs to pivot both ways. You can do this with a ball and some anti-rotate feature or you can have a pivot each way. One on top of the other. Each has some benefits and draw-backs.
 

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hey----the mans name is doug bath---most his work there is in boats/jet skis/atv/jeeps----his shop where i live is called proformance diesel (mispelled) that is now run by his nephew----i dont have his phone or shop name there though....
 

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Discussion Starter · #12 ·
After quite a bit of online reading I think I am going to look at a Dodge Neon 5 speed cable shifter. I'll post what I find out. I have read a lot of past posts here about this problem. It seems like several others have had the same issue of trying to keep the MSA transmission but have run into the shifter problem.

I do have a Ford Adapter, flywheel and starter from a 4BT and a Ford small block ZF so I can always get the Cummins to Isuzu adapter that bolts to my 4BD1T from diesel adapters if it comes down to it... And that might be my best option, just trying to keep my costs in check on the build.
Rick
 

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In the past I used a cable shifter from a small Toyota front wheel drive sedan. I didn't like the tight 180 degree bends and routing the cables made.

My next attempt will either, use the same Toyota shifter, but with links to replace the cables, or the high/low shifter used with some Land Rover transfer cases (with links to the pair of shift levers on the Isuzu gearbox.

The top lever on the Isuzu box selects the shift fork and the lever on the side moves the fork forward/neutral/rearward.

The orientation of the top lever can be changed by cutting and welding. The shifter needs to turn the top lever in the clockwise direction (viewed from above) when moved left to select a shift fork for a lower gear (or reverse).

If the shifter is further back from the shift levers on the MSA box, it will need a bell-crank to change the left/right lever direction to a for/aft motion of the lin k to the top lever on the MSA. The Toyota cable shifter I used does this, I just need to modify it with appropriate links to replace the cables.

Sorry I don't have a better pic of it. The left hand cable from the Toyota shifter selects the shift fork and is pushed/pulled by a bell crank on the side of the mounting bracket when the gear lever is moved left/right.

 

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One other thing you might want to know. Here is my shift pattern

R 2 4
1 3 5

Japanese trucks seem to like putting 5 and R as far apart as possible. Where Japanese cars like to put 5 next to R.
 

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Discussion Starter · #16 ·
the hydraulic shifter operates the same way with hydraulic lines instead of the long cables that have to loop all over.....
The hydraulic shifter has my attention, I guess tee off the power steering for hydraulic pressure? I guess you have a '64 Savoy? I have a '66 Belvedere 2 door hardtop project, a daily driver early 65 D100 stepside with mid 80's 318/727 and a D500 car hauler just sold.
bush65..thanks for the pictures and the explanation of how the shift levers on the transmission work.
Dougal, that is the same shift pattern that I have.

Thanks guys, keep it coming, we'll figure this out..
Put a GPS in the NPR, with the 19.5's got to 70MPH, she wants to cruise at 60 to 65 fine with the stock rear ratio and the MSA no overdrive...just about right for me.

Rick
 

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G'day Rick,

I have a MSA gearbox in my series 3 land rover which has been converted to a top shifter. I will be overhauling the box in the next few weeks, so can get some pictures of the shifter assembly if you like

Cheers Paul
 

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Discussion Starter · #20 ·
Hey Paul,

Pictures would be great....I have a 2002 Dodge Neon Shifter and cables on the way I will keep the post updated on how that works out. Got them pretty reasonable on E-bay. Still trying to figure the closed system hydraulic shifter out.

With the current lack of adapters for the 4BD1T may be more of us trying to figure out a way to keep the 5 speed Isuzu MSA.

Thanks
Rick
 
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