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datzenmike

DOGleg, euroSTYLE

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On a regular 5 speed front to back it's straight through (4th), 3rd...... 2nd,1st..... and in the tailstock Rev and 5th. Three pairs where a shifter in the forward position selects 1st, 3rd, or 5th. Pulling the shifter back can only give you 2nd, 4th or rev.

 

The dogleg front to back is 5th, 4th.... 3rd, 2nd and in the tailstock 1st and rev. Again three pairs but there is an extra linkage piece that reverses or flips the 1st/rev shift fork operation to give rev above 1st.

 

All doglegs will have an external bolt on the under side of the tailstock that holds this linkage. In the picture below the tranny on the right is a dogleg, (actually a Z series dogleg) but if you look where the rear mount would bolt to it and look just slightly to the right and down you will see a protruding bulge with a large nut on it. This holds a lever inside like a teeter totter that 'flips' reverse and first gear position on the shifter.

 

Mike,

You have the gear positions in the case correct for a standard pattern OD 5 speed but the Dogleg OD 5 speed gears are slightly out of order. The gears in position front to rear in the main case are 4-5-3-2 with 1 and R still in the tailstock. The front coupling ring still engages the 4-5 gears, but with 4th gear at 1:1, the coupling ring needs to be forwrd to drive the main shaft. To do this the shift rod needs to be moving the coupling ring forward as you move the shift lever forward for 4th gear. This is actually what the “teeter totter” or bell crank linkage in the tailstock is doing. By swapping the direction that the 4-5 coupling ring moves, 4th is 1:1 driving the main shaft and 5th can now be an OD ratio with the shift lever being in the right and down position.

 

There is an exception to the tailstock bolt/linkage rule. The Nissan Comp direct drive gearboxes are a dogleg pattern (also a 71 series with a “B” shifter). They DO NOT have the tailstock bolt or the "bell crank” linkage. The direct drive has 5-4-3-2 in that order in the main case and first and reverses behind the center plate, in the tailstock housing. Because 5th is 1:1 pulling the shift lever back to 5th moves the front coupling ring forward to engage the input and main shafts. This does not require a bell crank linkage like the OD dogleg 5 speed does.

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Yep, reverse and 1st are not in the same plane for OD dogleg, they are offset a little.

 

10121.jpg

dogleg shifter

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Mike,

You have the gear positions in the case correct for a standard pattern OD 5 speed but the Dogleg OD 5 speed gears are slightly out of order. The gears in position front to rear in the main case are 4-5-3-2 with 1 and R still in the tailstock. The front coupling ring still engages the 4-5 gears, but with 4th gear at 1:1, the coupling ring needs to be forwrd to drive the main shaft. To do this the shift rod needs to be moving the coupling ring forward as you move the shift lever forward for 4th gear. This is actually what the “teeter totter” or bell crank linkage in the tailstock is doing. By swapping the direction that the 4-5 coupling ring moves, 4th is 1:1 driving the main shaft and 5th can now be an OD ratio with the shift lever being in the right and down position.

 

There is an exception to the tailstock bolt/linkage rule. The Nissan Comp direct drive gearboxes are a dogleg pattern (also a 71 series with a “B” shifter). They DO NOT have the tailstock bolt or the "bell crank” linkage. The direct drive has 5-4-3-2 in that order in the main case and first and reverses behind the center plate, in the tailstock housing. Because 5th is 1:1 pulling the shift lever back to 5th moves the front coupling ring forward to engage the input and main shafts. This does not require a bell crank linkage like the OD dogleg 5 speed does.

 

Thanks Dave I was trying to work it out in my head and got it wrong. Yes the F5C71B? is a DD 5th and only found out they were a dogleg pattern recently. I guess there aren't a lot on the street.

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There are 71B that are Direct-fifth, and 71B that are overdrive. The Direct-fifth ones (F5C71B) are from Nissan Competition/Datsun Competition. Did they ever come in production cars?

 

2000 Roadster came with a direct-fifth, but it was FS5C71A with separate bell housing.

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There are 71B that are Direct-fifth, and 71B that are overdrive. The Direct-fifth ones (F5C71B) are from Nissan Competition/Datsun Competition. Did they ever come in production cars?

 

 

Not in N Am. Maybe not at all.

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My 510 had the dogleg transmission hooked up to a L20B in it when I bought it 4 years ago. Weird at first but I actually came to really like it after a while.

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It's a definite advantage if you don't stop or at least need to use 1st gear that much. (like racing) The 1st to 2nd shift is rather slow, a disadvantage, otherwise it's unique and has a cool factor.

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sorry to open up an old thread,

I'm planing on using a UK 810sss dogleg box in my 510,

ratio's as follows

5SPEED

1st 3.382

2nd 2.013

3rd 1.312

4th 1

5th 0.854

rev 3.57

and for interest

UK 4 speed from 810 also

1st 3.382

2nd 2.013

3rd 1.312

4th 1

rev 3.364

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Good to know. Will file that away for sure. Thank-you.

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