Trans recommendation for Dat/Nissan A series?
- Thread starter Eric P
- Start date
peterzekert
Well-known member
Eric P. Tell your friend he can give me a call and I can fill him in on the options.
The 4-speed Comp ratios were just better ratios for the stock 4-speed 56 boxes. They are narrow width gears and they do break, even in vintage cars. These were all brass cone syncro gears. Replacement parts are very tough to find used. New-old-stock parts are ultra rare.
The 5-speed Comp stuff, called the F5C56A gearboxes, were designed with a few mm wider gears and with steel band syncro rings. Most of these were broken in the 1990s as the power outputs on GT4 cars and some GT5 cars could break gears at will.
Parts are almost impossible to find for these boxes. I have shipped a rare gears to China, South America, Europe, New Zealand, Australia or South Africa. If he uses one of the Datsun Comp options he will be SOL if it breaks.
Dan Hall made a 5-speed Hewland Mk9 box based on a Datsun B210 A-series case. Dan's boxes had two problems which we rectified. [Everyone experienced them.]
The first was breaking the lower front countershaft bearing (a stock Datsun piece) which would allow the countershaft to drop away from the mainshaft and teeth would skip. We set a steel sleeve in the aluminum case to support the bearing, solving this problem.
The second problem was the selector fork sticking in one shift rod while the next shift rod was engaged in gear. 2007 Runoffs I finished the second half of the race with the shifter in the 2nd-3rd gate but with 4th gear engaged. We've solved that problem too by making sure the detent locations are right in the middle of the two gears; by using aftermarket detent springs; and by checking the wear on the selector finger. When it happened to me in 2007 was my brain fade. I screwed up.
Good working units are available and all of the parts are available for Dan's gearboxes. I can help your friend locate one. I can help him locate anything.
Peter
The 4-speed Comp ratios were just better ratios for the stock 4-speed 56 boxes. They are narrow width gears and they do break, even in vintage cars. These were all brass cone syncro gears. Replacement parts are very tough to find used. New-old-stock parts are ultra rare.
The 5-speed Comp stuff, called the F5C56A gearboxes, were designed with a few mm wider gears and with steel band syncro rings. Most of these were broken in the 1990s as the power outputs on GT4 cars and some GT5 cars could break gears at will.
Parts are almost impossible to find for these boxes. I have shipped a rare gears to China, South America, Europe, New Zealand, Australia or South Africa. If he uses one of the Datsun Comp options he will be SOL if it breaks.
Dan Hall made a 5-speed Hewland Mk9 box based on a Datsun B210 A-series case. Dan's boxes had two problems which we rectified. [Everyone experienced them.]
The first was breaking the lower front countershaft bearing (a stock Datsun piece) which would allow the countershaft to drop away from the mainshaft and teeth would skip. We set a steel sleeve in the aluminum case to support the bearing, solving this problem.
The second problem was the selector fork sticking in one shift rod while the next shift rod was engaged in gear. 2007 Runoffs I finished the second half of the race with the shifter in the 2nd-3rd gate but with 4th gear engaged. We've solved that problem too by making sure the detent locations are right in the middle of the two gears; by using aftermarket detent springs; and by checking the wear on the selector finger. When it happened to me in 2007 was my brain fade. I screwed up.
Good working units are available and all of the parts are available for Dan's gearboxes. I can help your friend locate one. I can help him locate anything.
Peter
Matt Blehm
Moderator
Peter, while you're in the process of giving advice, mind helping out another n00b?
I'm running a 240SX in STU (drivetrain options are open, max 6 spds) with a KA24DE and looking for options. The G force T-5 sounds really nice since I can use my existing 4.1 and 4.6 differentials with the OD, but they're discontinued and parts are are going to become rare soon.
current power output is stockish (160or so), but I'm going to be doing an engine build this fall and planning ~225-250hp in the end.
I'd rather pick up a 5 spd w/ overdrive so that I can use gears 3,4,5 on the longer tracks and 2,3,4 on the shorter ones vs. having to swap rear ends every event (that's a 1-2 hr job in this car without a lift).
Been calling around for prices and advice and I've been told the Jerico 5 spd and Quaife sierra are both nice boxes-- by the guys that make their living selling and servicing them...
A local friend that runs a 240SX in EP has told me to avoid the Quaife and Taylor boxes at all costs. Of course the advice is worth what I paid for it, but I do trust the guy's opinion.
any ideas on options? Things to avoid?
Thx!
I'm running a 240SX in STU (drivetrain options are open, max 6 spds) with a KA24DE and looking for options. The G force T-5 sounds really nice since I can use my existing 4.1 and 4.6 differentials with the OD, but they're discontinued and parts are are going to become rare soon.
current power output is stockish (160or so), but I'm going to be doing an engine build this fall and planning ~225-250hp in the end.
I'd rather pick up a 5 spd w/ overdrive so that I can use gears 3,4,5 on the longer tracks and 2,3,4 on the shorter ones vs. having to swap rear ends every event (that's a 1-2 hr job in this car without a lift).
Been calling around for prices and advice and I've been told the Jerico 5 spd and Quaife sierra are both nice boxes-- by the guys that make their living selling and servicing them...
A local friend that runs a 240SX in EP has told me to avoid the Quaife and Taylor boxes at all costs. Of course the advice is worth what I paid for it, but I do trust the guy's opinion.
any ideas on options? Things to avoid?
Thx!
Matt, for your 240 its not just power, its weight also you need to consider. The Jerico and also a Saenz 840 would both be good options if you are allowed a Dog Box. Quaife does have a 5 spd that would work for you also. Problem with Quaife is parts cost and availability. The Jerico is probably your best option all around. If money was no object a PBS or a Holinger would also suffice.
Chris
Chris
Matt Blehm
Moderator
thanks for the input.
trans is unrestricted- 6 forward speeds max. Sequentials get a 100lb weight penalty.
My car is ~2700lbs currently. min weight with this engine is 2640. If they legalize the SR20DET, then I'll get the car as light as I can and size an inlet restrictor for the turbo based on my main attainable weight. nonetheless, I'll be in the 2600-2700lb range.
One of the problems (same as with your car) is the tranny tunnel is narrow. I'm not sure if I'm allowed to cut the tunnel to fit or not.
I had a line on a Saenz 840 a while back and lost touch with the guy. found his info again last month and it was sold. the older Saenz TC840 units were vertical arrangements, while the newer ones are side by side shafts. that makes for better ground clearance, but not for body clearance.
As for the Quaife, Taylor Racing Engineering in Dallas area (200miles away) stocks their trannies and I would *assume* parts for them. They have a comprehensive list of parts on the website, but I'm not sure how much of it they actually stock.
there's options out there, but hoping to get some input from guys that have run this car and/or engine for some tips on gearing with the factory diff ratios.
trans is unrestricted- 6 forward speeds max. Sequentials get a 100lb weight penalty.
My car is ~2700lbs currently. min weight with this engine is 2640. If they legalize the SR20DET, then I'll get the car as light as I can and size an inlet restrictor for the turbo based on my main attainable weight. nonetheless, I'll be in the 2600-2700lb range.
One of the problems (same as with your car) is the tranny tunnel is narrow. I'm not sure if I'm allowed to cut the tunnel to fit or not.
I had a line on a Saenz 840 a while back and lost touch with the guy. found his info again last month and it was sold. the older Saenz TC840 units were vertical arrangements, while the newer ones are side by side shafts. that makes for better ground clearance, but not for body clearance.
As for the Quaife, Taylor Racing Engineering in Dallas area (200miles away) stocks their trannies and I would *assume* parts for them. They have a comprehensive list of parts on the website, but I'm not sure how much of it they actually stock.
there's options out there, but hoping to get some input from guys that have run this car and/or engine for some tips on gearing with the factory diff ratios.
Kerry Foote
Well-known member
Peter, I own a Dan Hall 4 speed and am having the same problem you had with the shift fork shaft. When I shift from 2nd to 3rd it appears to me that the 1st/2nd shift rod goes up to 1st while the shifter goes to the 3rd. It seems to happen no matter how careful I am when shifting. You said you used different detent springs Could you tell me where you sourced them? Thanks. Kerry
peterzekert
Well-known member
Kerry,
There are two things going on at the same time. Dan welds a small square pad onto the shift finger of the 5 speed so that it can get to the relocated 1st gear shift rod. That pad gets a little worn and it can slip between the shift rods leaving you stuck in one gear with the shifter finger in the next. Same for the 4 speeds if the finger is worn or rounded. Build that part of the shift finger up, BUT NOT TOO MUCH, and then file it down square, BUT NOT TOO MUCH.
Now you're asking, "how much is too much and how much is just enough?" I have a tailhousing that I use as a fixture with a hole the size of a softball that allows me to see how the shift finger/shift rods are in relation to each other.
On the detent springs, I went hunting for a stronger spring. I found that some Z cars and L-series stuff had a better spring. I also found some after market springs. Sorry I don't have the part numbers.
I also made sure that when my shift dog rings were in neutral, middle between each pair of gears that my detent mark on the shift rod was in the middle of the detent hole. I had one shift rod where the detent "neutral" was pulling toward one gear. I had to replace the rod.
Call or email if you want more explanation. Peter
There are two things going on at the same time. Dan welds a small square pad onto the shift finger of the 5 speed so that it can get to the relocated 1st gear shift rod. That pad gets a little worn and it can slip between the shift rods leaving you stuck in one gear with the shifter finger in the next. Same for the 4 speeds if the finger is worn or rounded. Build that part of the shift finger up, BUT NOT TOO MUCH, and then file it down square, BUT NOT TOO MUCH.
Now you're asking, "how much is too much and how much is just enough?" I have a tailhousing that I use as a fixture with a hole the size of a softball that allows me to see how the shift finger/shift rods are in relation to each other.
On the detent springs, I went hunting for a stronger spring. I found that some Z cars and L-series stuff had a better spring. I also found some after market springs. Sorry I don't have the part numbers.
I also made sure that when my shift dog rings were in neutral, middle between each pair of gears that my detent mark on the shift rod was in the middle of the detent hole. I had one shift rod where the detent "neutral" was pulling toward one gear. I had to replace the rod.
Call or email if you want more explanation. Peter
Kerry Foote
Well-known member
Thanks Peter, I just happen to have an old 280z trans in the shop. About welding on the finger,I thought it was hardened and that would tend to soften the material.
peterzekert
Well-known member
Kerry, As the corners on the end of the shifter finger get rounded, it is more able to "slip through" or "slip between" two nearby shift rods. The finger needs to be fairly squar-ish so it can only be engaged in one shift rod at a time.
Do you want to send me, or post a photo of your finger? [Insert bad joke here.]
Peter
Do you want to send me, or post a photo of your finger? [Insert bad joke here.]
Peter
Kerry Foote
Well-known member
The tranny is still in the car, but when I take it out I'll get back to you. I seem to remember that the finger is kind of oval shaped, like a square with the corners rounded off. I have a spare stock trans I can look at also. Thanks for the help.