FS5W71B Rebuild Thread - Tips tricks and discoveries!

[zKars]

Two bearing kits came in today. One from Nissan, one from drivetrain.com. One more to come from transmissionpartsdistributors.com/. They are taking their sweet time shipping. Someone made the label with USPS software, but so far nothing has gotten TO USPS to get on its way to me. Slackers.

I will take the kits apart and compare for you at some point.

 

[zKars]

I'm watching Youtube again to watch how the three major rebuild videos are doing their reassembly again. Thought I'd list them here for reference in one place.

All are good their own way, each is different. 

1. Dave WM. Video's part 1 to 13. All are called " FS5W71B datsun 280zx transmission rebuild pt X" where X is 1 to 13  (1-13). Some use the word PART instead of pt. I am not putting the URL's for all 13 in here. Actually there is a 3.1, so there may be 14 parts officially.

2. Greg Oslund. Video's call "Datsun 280Z 5 Speed Transmission Rebuild". Single 1:43:00 video doing the whole thing end to end. The description gives a list of the topics covered in what time periods in the video to help you skip ahead to the parts you care about.

0:00 - 28:00 Disassembly 28:00 - 33:00 Intermediate Plate Assembly 33:00 - 45:00 2nd/3rd Gear Assembly 45:00 - 49:40 Press Mainshaft into Int. Plate 49:40 - 52:00 Countershaft into Int. Plate 52:00 - 59:00 4th Gear Mesh with Countershaft 59:00 - 1:02:00 5th and Reverse 1:02 - 1:10 Mainshaft Nut Torque 1:10 - 1:13 Countershaft Nut Torque 1:13 - 1:18 Tail Bearing and Speedo Gear 1:18 - 1:29 Install Shift Rods/Forks 1:29 - 1:30 Final Inspection 1:30 -1:34:30 Case Assembly 1:34:30 - 1:38 Countershaft Shim in Front Cover 1:38 - End Wrap Up/Lessons Learned

3. villageland.  This is the silent asian gentleman showing how to tear down and re-assemble an FS5W71B. There are three parts.

 

[zKars]

Ok, pics of what I got from drivetrain.com, kit BK104WS

Nicely organize, everything is there, and best of all, the bearings at least claim to be of Japanese origin!

you only get the one needle bearing. It is for either the 5 gear or where the front cluster attaches to the main shaft. It's construction is definitely "different" than the originals, or the ones I got from Nissan. Doesn't mean its worse but the cage is definitely more coarse looking. 

Edited December 11, 2019 by zKars

[Dave WM]

when you get around to the front cover, use some sealant all around that gasket. It looks like the same one I used from a rebuild kit, ended up leaking by the shift rod area.

I would use the red anaerobic stuff, just a thin film on both sides of the gasket. also sealant on the thru bolts that connect the front cover to the housing.

[zKars]

Excellent advise Dave. 

When I read the descriptions of all the different gasket makers, adhesives, sealants etc, I find it all highly confusing. Just go read about these products on Permatex website. I guarantee you will be confused on what to use in what situation. Sealants can be gasket makers and sealants. Gasket makers don't seem to be great sealants.

My favorite example is when I look at the gasket making products, and come across the category for Anaerobic gasket makers and sealants!!!! Even they can't keep the two apart. ANd then there is whole section on "Gasket Sealants". https://www.permatex.com/product-category/gasketing/gasket-sealants/  Arghhhhhh!!!!

No wait. This stuff Permatex^® High Tack^™ Spray-A-Gasket^™ Sealant, is actually an adhesive! It's for sticking gaskets on metal surfaces. Dear lord.....

All I want is no leaks and to use fewer paper gaskets.

Reading this tonight, it does clear up some of the areas that I have never seen clarified properly about proper use of sealants and gasket makers. Give it a read. Especially RTV gasket makers vs Anaerobic flange sealants. At least it makes it clear how to use each one properly.

https://www.permatex.com/ten-common-gasketing-mistakes/

Oh, and the "right stuff" seems like magic. 

Edited December 12, 2019 by zKars

[240260280]

I reused the 3 large paper gaskets on an early transmission rebuild.  Aviation gasket sealer did the job nicely.

Just coat the gasket surface AND the mating surface then wait 5min before fastening together.

Edited December 12, 2019 by 240260280

[grannyknot]

9 hours ago, zKars said:

Reading this tonight, it does clear up some of the areas that I have never seen clarified properly about proper use of sealants and gasket makers. Give it a read. Especially RTV gasket makers vs Anaerobic flange sealants. At least it makes it clear how to use each one properly.

https://www.permatex.com/ten-common-gasketing-mistakes/

That is good info, Permatex makes a black polyurethane adhesive/sealant #59503 that they don't even list on their site.  It is very versatile and also makes a great gasket on anything except high heat applications.

 

[Dave WM]

yea I know the gasket/sealant info is VERY confusing at times.

51813 peratex

[wheee!]

Off topic, but I just bought this to adhere the new rubber seal kit I bought to the car!

[zKars]

Back on topic

Way in the back of the tranny garden (forest?) I remembered I have a 720 truck five speed! I've been ignoring it because it has a bell housing I can't use on a Z or 510, anything with a tilted L series. Outwardly it looks identical to any long eared one-muffler hanger FS5W71B except for a couple of key details. The wrong bell housing for one, and the fill plug is on the other side of the case. 

Look here to review the differences if you're not on top of that.

https://ratsun.net/topic/74205-620-transmission-identification/

BUT this sad little truck trans IS a donor for my worn out 1/2 shift fork! They are identickle!

Took it apart today, and it's in perfect shape. 

Gear ratio's are interesting. Being a truck, first is a bit of a stump puller.

1	3.592
2	2.246
3	1.415
4	1
5	0.813

 

Let me say here that I am actually not a fan of the much coveted "close ratio" 5 speeds. Gotta say I've had just about enough of the fawning and slobbering over their supposed greatness. 

The 2-3-4 ratios are nice and close, wonderful for road racing I suppose, but first is about 2.5 miles away from 2nd. I've always been a bit ticked about the huge gap between 1 and 2 in both my Z and now my 510. Not ideal at all for tight auto cross circuits. SO!!!!

I going to hypothesize that I like the above truck ratios for 1-4. Now the Z close ratio 5 has that nice .745 overdrive, while the truck has a so-so .813, but I have a solution. I'm going to put the lovely .745 5th gear gear bits from my Z trans into the back side of this nice truck cluster. It's all separate gears behind the intermediate plate, just gotta take ALL the parts from one and stuff them in the other. BWAHAHAHAHAHA!!!

THEN when I break it next I'll stuff the C type in there and live with it's ratio's.

You know, a guy could get the bell housing machined for the 62 mm front counter shaft bearing, and strengthen up a B type pretty nice. It's the bearings that give out, never busted a fork or gear set. Who needs those fancy C types with their longer length, wider gears and skinny syncro's anyway? ( read that with a sneer pls).

 

Edited December 16, 2019 by zKars

[zKars]

Alas, I am but a dreaming fool. My plan above to use my .754 gear set will actually make the 5th ratio a stupid 0.900.

You have to account for the 4th gear main/counter gear ratio to correct the actual 1, 2, 3 and 5th gear tooth count ratio's to get the total drive ratio.

With the close ratio, the 4th gear teeth are 23 vs 29 or 0.793 ratio, then apply that to that actual 5 gear tooth ratio,  which are 26 and 44 = 0.593, / 0.793  = 0.745 actual 5th drive ratio.

But do that with the truck 5 speed gears, 4th main and counter are 26 and 44, or 0.591. so with my 5 gear stuff. is 0.593 / .591 and you get a utterly heart breaking 0.90 5th ratio.  Not doing that! 

But!!!!! As I'm typing I'm thinking more (haven't learned my lesson yet...), I could ALSO use the 4 main and counter gears from the close ratio in the truck trans (the only gear you can remove and replace on the counter shaft hahahah), which would give me the 0.745 5th, but wait, oh crap, it will also screw up all the other 1st and 2nd and 3rd ratio's as they are corrected by the 4 main/counter ratio. Let's see how bad is that....

So I have two sets of 5th gear gears, and two sets of 4th gear gears, so could build 4 different ratio sets. Let's be scientific and get Excel going. One of these combo's "might" be worth trying.

 

720_trans_ratio.xlsx

Edited December 16, 2019 by zKars

[Zed Head]

Meet your doppelganger...

https://forums.hybridz.org/topic/110792-high-rpm-shifting-dynamics/

Don't overlook the need to match the transmission ratios with the diff ratio.