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1987 FLU419 SEE
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Discussion Starter #1
I recently purchased a 1987 FLU419 SEE.. Excited! I am in need of a little information on a transmission issue. When I select Gear box (I)(lower speeds) and shift through 1st through 4th no issue, however when gearbox is selected to (II)(for higher speeds) and I start to accelerate the Mog locks up the wheels (skid)! Do any of you have a thoughts and or suggestions? I'm crossing my fingers for a little luck:) Thank you in advance.

Mog Newbie!
:laugh:eek:eek
 

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Your description is a little odd and you are probably going to have to do a lot more diagnostics to get a closer answer.

One possibility would be that the low gear/high gear assembly is misaligned, causing the low gear to re-engage while still in high range. That would lock the transmission (probably damaging it rather badly) and require disassembly/fixing the gear forks.

...Thinking about it a bit more, a second possibility is that you are slamming it from 4th gear low range to 1st gear high range? If so... DON'T DO THAT!
 

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1987 FLU419 SEE
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Discussion Starter #3
Transmission issue on FLU419 SEE

Your description is a little odd and you are probably going to have to do a lot more diagnostics to get a closer answer.

One possibility would be that the low gear/high gear assembly is misaligned, causing the low gear to re-engage while still in high range. That would lock the transmission (probably damaging it rather badly) and require disassembly/fixing the gear forks.

...Thinking about it a bit more, a second possibility is that you are slamming it from 4th gear low range to 1st gear high range? If so... DON'T DO THAT!
I can tell you it's not me slamming gears for sure, nor would I try that kind of shifting method when not completely sure on how the shifting actually works. When you say low/high misaligned how can I find that out?
 

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What I mean is that 4th gear low range is not continuous gearing with 1st gear high range, you do not start in low range, accelerate, and then switch to high range. Low range is for offroad/slow operation, high range is paved road driving. 1st gear high range is a lower gearing than 4th gear low range. So correct operation is to use 1st thru 4th gears in low range when needed, then stop, shift into high range, and use 1st thru 4th on the road.

1st thru 4th are exactly the same gear sets for both the low and high ranges. The difference is that in low range the transmission input shaft (well... really the cascade output shaft, we'll ignore that for the moment) drives the reduction shaft, at the front of the main transmission body. The reduction shaft then drives the main shaft at 3.21:1 ratio thru the forward/reverse collar (in reverse the reduction shaft drives the countershaft). The main shaft contains the 1/2/3 gear sets, meshed to the counter shaft, and 4th which is a direct coupling to the output shaft. In high range, the input shaft is directly coupled to the mainshaft via the high range collar and the forward/reverse collar is disengaged. the same 1/2/3/4 gears and collars are used.

So if in low range (and reverse) you can shift and drive thru all gears without issue, under all conditions, and then in high the transmission immediately locks up in all gears, then the problem is in the low/high collar and forward/reverse collar engaging in the wrong order, not the 1-4 gear collars. Knowing exactly where the problem is, is not possible without more diagnostics and at a minimum removing the cover plates. (Of course, if a bearing/gear is broken and chips are flying about, it could be the locking up in both ranges and you just haven't experienced it yet.)

I don't recall seeing a good power flow diagram for the UG2/30 transmission, but the function is basically the same from 404 to 406 to 419. Below is an annotated 419 transmission from memory.
 
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