Wanted: L20b and a dogleg

[Masterblaster68]

Hello I am looking for a l20b and a five speed transmission, I would prefer a dogleg if possible.

Thanks

[RMS]

if you are in Vancouver I could offer you your choice of l20b and dogleg but no one knows were you are.

[Masterblaster68]

Sorry, I am in San Jose Ca.

[RMS]

for the cost of shipping you could get a race ready rebello. hopefully some one closer has what you want.

[datzenmike]

The 'dogleg' was only available in the first gen '77-'79 S10 (200sx) and as an option in the A10. Not a lot around and those that are will be well used. An easier 5 speed to find would be the FS5W71B found in the 280z, 280zx (non turbo), 810 and Maxima 620 and first year 720 2wd trucks. Lots of those made and built to handle a six cylinder or truck so much much stronger. Came in wide, mid and close ratio gear sets too. You will have to modify the transmission mount no matter what transmission you use so the only disadvantage is the 71B is 5.5" longer so your driveshaft would need shortening.

[tycot1]

who run Bartertown?

[McShagger510]

master_blaster_by_phleitodactilo-d4x9oyp.jpg (193.43 KiB) Viewed 3828 times

[Byron510]

You know, these trannnies take a bad rapp..... it I need to enter my two cents.

In 2003 when assembling the Bronze, I neglected to get the close ratio ZX box rebuilt, so at the time of assembly I installed an unknown dog leg SX box borrowed from Rob, as it was offered at the time. This was to be a stop gap measure 'until I get the ZX box overhauled'! The Bronze went into immediate battle. During its first 10 years, only Yoko A032's were installed, many autocross events were attended where I drove hard and placed well, and most importantly I drove it for what it was worth the whole time. A couple different dyno sessions agree that around 150hp is reaching the rear wheels through a few different LSD equipped rear ends. And today, some 14 years later, and just under 500 hours on the meter - that temporary ' SX box ' still lives. In fact the rebuilt transmission has been twice sold, and I had another rebuilt to have on the shelf for that 'one day upgrade'. The shortened and Ballanced drive shaft sits right beside it. Oh, and I did I mention I have had to replace the Roadster clutch through this as well - testimony that the miles have not been 'easy going'.
So I have to wonder, how 'weak' are these supposedly inferior transmissions? Granted I'm not a 'neutral drop' kind of guy, and there haven't been too many burnouts over the years. But there has been no shortage of hard launches - I rarely let the chance slip by. And I've been known to bang a few shifts now and again. And I have also, like many who've drives a dogleg, done the inadvertent 5-2 downshift. But I think that's been harder on the valve train and rods than the transmission.
Thanks Rob for the extended use of your transmission, it it s still good to go and not in any immediate need to swap out!
And I hqve another dog leg SX core laying outside which came out of a perfectly good running car, but the OP just lived too far away to make that trip reasonable.

Byron

[Three B's Racing]

Gotta agree with Byron as I too ran a dogleg trans in my first two 510's with the same trans transfered. Only time I got rid of the trans was when the 510 was sold prior to my moving East in `89. That trans like Byron went through it's share of hard knocks and likely many more miles as my 510s were dailys at that time.

[zKars]

Very interesting stories of actual experience verses assumed design limits. I'd love to hear stories what failed in doglegs that went boom in the past. Shearing shafts? Bearing go boom? Case splits? Gear teeth becoming polishing compound for other gears?

I promise I shall thrash the dogleg I have in my 200hp beast as hard as possible with little regard for its feelings or longevity. I suggest we consider transmissions as wear items like clutches and brake linings; and tires; and windshields. Ok, enough....

[datzenmike]

Assumed design limits? I can only comment on the 71B 4 and 5 speeds. My current 5 speed in my 710 (for about 4 years) was the replacement for my 620 truck transmission for at least 10 years and was originally found by accident in a scrap metal yard in a crushed vehicle sometime in the mid 90s. I thought it was a four cylinder L series but it was (unknown to me then) a '79 280zx the only year with the mid ratio 5 speed option. How many miles??? No idea but it's in it's third vehicle now. I replaced the tail with the one from an '85 720 diesel to get the short throw shifter and reverse check sleeve.

Two cents....

I did say the 71B was much much stronger and made no comment on the dogleg's strength directly. The dogleg is an adequate transmission and wasn't used on engines over 2 liters. I did say that the 71B was designed for use in the six cylinder Z cars through the 280zx non turbo (150 ish net hp) and suitable for truck (ab)use.

The FS5W63A dogleg has 63mm or 2.48" between the center line of the main and counter shafts. The FS5W71B is 71mm or 2.79" allowing more room for larger bearings and larger thicker gears.


The counter bearing (bottom one) by far receives the most abuse. If your transmission growls, this is likely the cause. Here is a 71B left (56mm or 2.2")and a much smaller roller bearing on a dogleg (42mm or 1.65")...



Much later 71Bs were upgraded with a larger 62mm counter bearing to try to cope with increasing 4 cylinder displacements and six cylinder power levels. Better synchros and even a reverse check sleeve to block down shifting into reverse was added.

If the dogleg is adequate, imagine how much more adequate a 71B transmission must be.

[tycot1]

Thats what i was hoping for, thanks James.