5 speed rebuild kits

[shacks510]

So my Z/ZX 5 speed (early case) sounds like glass in a blender when the trans is turning with RPM. It's a constant chatter sound like glass in a blender when I'm driving or rev it in neutral. It's definitely the trans because I can feel it in the shifter. It's a constant sound in all gears, so it must be main shaft? Not sure if it's a bearing or a syncro that's flopping around. I didnt try revving it stopped in gear with the clutch in to seperate engine from main shaft. It drives and shifts fine with no grinds, it just sounds terrible. I was 20 miles from home and wasn't going to risk grenading it, so I had it towed. I haven't drained the fluid yet to see if anything comes out that shouldn't.

 

I was sent this, and they actually list 71B rebuild kits. Also 71A for Z/ZX which I've never heard of.

 

http://www.drivetrain.com/parts_catalog/manual_transmission_overhaul_kits/nissan_f5w71_overhaul_kit.html

 

... Thoughts?

[datzenmike]

Does it make noise in reverse backing up?

 

ALL gears are spinning anytime the engine is running and the clutch is up or out. So it could be the counter bearing.

 

 

 

 

The FS5W71A (bottom above) was a 'warmed over'  roadster 5 speed with an L series bell made for it, for use in European Z cars. Some found their way over here back in the day by dealerships ordering them for Z car owners here. The 71B 4 speed didn't come out till '71 and the '71B 5 speed not till '77.

 

The F4W71A was the standard 4 speed for the Z car for '70. In N America.

[shacks510]

I didn't pay attention to any noise while backing up the couple feet I did

[DanielC]

The main shaft only rotates when the rear wheel are turning.   With the engine running, and clutch pedal not depressed, and car parked, (in neutral) the input shaft is turning, the cluster gear (countershaft gear) is turning, and several gears are turning on the stationary main shaft.

 

If it is the input shaft bearing, it might be possible to drop the transmission, pull the input shaft out through the bell housing, get to the bad bearing, and have no more work to do.

 

If you get a lot of metal pieces out when the oil is drained, you do need to take the transmission apart more to inspect everything.

[shacks510]

The main shaft only rotates when the rear wheel are turning.   With the engine running, and clutch pedal not depressed, and car parked, (in neutral) the input shaft is turning, the cluster gear (countershaft gear) is turning, and several gears are turning on the stationary main shaft.

Ah, that makes sense. I'm going to crack open to see what's inside. I opened and inspected it after I bought it to make sure everything looked ok, and felt the accessible bearings for smooth rotation. Everything seemed good, so I sealed it back up.

 

If I can get a rebuild kit, I'll spend the extra time and money, so hopefully I don't have to do it again.

[datzenmike]

Start by doing what you can from the outside... check the oil level by removing the bung about half way up the side of the transmission. For some reason the zx transmissions tend to have the bung on the right side but if not, directly across on the left. Stick your finger tip in and if you can touch the oil it's full. If not top it up and see if that reduces the noise. Next drain the oul out the very bottom bung. Even old oil should be clean and see through. Look at the magnet on the drain bung for metal chunks. A black paste and fine dust is normal.

[G-Duax]

Be careful of any 'kits'.

I have bought them for both Nissans & Toyotas, and never once received a full set of bearings.

Tipicly they will mis some of the odd-ball needle bearings, or races.

 

The last 71B 5-speed I did had a bad inner race on the input shaft first gear.

Had to buy an industrial one, that was close, and shorten it 2mm.

[shacks510]

Well I guess I'll find out if it's complete when I get one...

[shacks510]

UPDATE

 

I dropped the trans and pulled the clutch off. This might be my problem.

 

https://youtu.be/X4TjlNe72TQ

[datzenmike]

I think that's normal. You would never hear those (with transmission wrapped around them) even if they could rattle. Centrifugal force even at idle would hold them in place.

[shacks510]

I thought about that, but I disagree. I picked up an Exedy friction disc to compare, and there is no wiggle in the springs. There are four of the same size springs instead of six.

 

I opened up the transmission again, and nothing looks amiss. The bearings I can put my hands on feel smooth with no wobble, and the synchros all look good and only spin about 6mm each way. No chunks came out as I drained it, but there was what seemed like an excessive amount of metal paste on the magnet. This fluid only had about 500 miles, and those are all the miles I've put on this transmission since I bought it. Unless it's one of the bearings in the center housing, then I may have well been the clutch springs. Flywheel bolts are tight.

[datzenmike]

Those springs are always loose on used clutch discs.

 

Shake it hard and listen. Now imagine it being several feet away, wrapped entirely with 1/2" of aluminum, then sheet metal floor, and last some kind of carpet, maybe some sound deadener. Now with the engine running. 

 

 

If those springs are one ounce each (29gr) and are on a 4" diameter (I measured one I have) and you are idling at 850 RPM the centrifugal force is 40.39gee. Or 40 grams... or 2.5 pounds. That's 2.5 pounds pulling outward on them. They are not going to rattle.

 

At 4,000 RPMs it's over 30 pounds.

[shacks510]

I really don't know. I should get new bearings since the trans is open. I'd hate to put it back together as is with the new clutch disc and have it make the same noise, or put new bearings in and use the old clutch, and find out it was the clutch. If I put new bearings and clutch disc, then I won't know which was causing a problem.

[datzenmike]

Did the input shaft turn smoothly? Put the shifter in it and try each gear.

 

Was the magnet cleaned after you bought it? This would show only the wear that you put on it.

[shacks510]

After I bought the transmission, I drained the oil, cleaned the magnet, and opened the case to take a look at everything I could see and feel, aside from the center bearings, and everything seemed good. The magnet did not have any odd chunks; just the normal metal paste.

 

Thinking about it, ever since I started driving on this transmission and clutch combo, I've been hearing a slight chattery sound, but I didn't think much of it. The last time I drove the car before the noise was awful, I went on a 140 mile round trip, and didn't notice any louder than normal sounds.

 

I did some more searching, and found this. I don't remember what I heard when I went into fourth gear getting off the freeway. I was probably thinking too much about the other noise. I was driving slow enough on the street that 4th wasn't needed. But I might be onto something...

1st, 2nd, 3rd and 5th gears are driven by the counter shaft. Power from the mainshaft (from the clutch) is transferred by gears down onto the countershaft and depending on which of the 1,2,3 or 5th gears is selected, back up onto the mainshaft again and out the tailshaft. The countershaft runs parallel to the mainshaft and supported by bearings.When under load the main and counter shafts try to force each other apart and the bearings job is to prevent this but allow them to turn efficiently. When one or more of these bearings wears out there will be noise in any one of the 1,2,3 and 5th gears or all of them. Why is there no mention of a 4th gear? Because there really is no 4th 'gear' in a five speed with overdrive. Forth is really transmitting power straight through along the mainshaft with one turn in to one turn out. It's relatively unaffected by bad bearings because there is no side load generated against the countershaft or it's bearings. This is why 4th is often much quieter than all the other gears.

I will need to call a more experienced friend over to help me remove the gears from the main and counter shafts so I can get to the center bearings.

 

(Link to entire thread quoted above: http://community.ratsun.net/topic/35174-transmission-noisechatter/ )

[kelowg]

What bout shifter bushings? U ck the diff. Mike is dead on bout clutch springs. Its more likely an issue somewhere else. Many clutches/trans have been replaced and have same issue afterwards. U sure trans isnt hitting/rubbing on the body or frame,ect. Now is the time to ck any and all drivtrain parts,vehicle is already down. 

[shacks510]

I dug into the trans more, and I think I found the problem. Bad countershaft center bearing.

 

https://youtu.be/5rydzgcgesc

 

I had talked to a guy that has experience rebuilding the 71B, and it's pretty involved. You have to take pretty much everything apart, and I don't have all the tools/equipment to do it. Replacing the countershaft bearings is less difficult than the rest of the bearings, so I'll be replacing just the countershaft bearings. Not the best thing, no, but I'm going to do what I can. Hopefully that fixes my issue.

 

Shake it hard and listen. Now imagine it being several feet away, wrapped entirely with 1/2" of aluminum, then sheet metal floor, and last some kind of carpet, maybe some sound deadener. Now with the engine running.

I agree. The clutch is still a possibility in my head, but I do think it's a transmission issue. I don't want to use the new disc I got if I don't have to. My current disc has lots of meat left. I'll hang onto it until I get the car back together with hopefully a happy sounding transmission.

[Scgreen620]

Check the bearings I'm having the same problem too.. I over hauled mine a year and a half ago and it's doing the same thing again

 

A guy told me it might be the drive shaft being too long since we lower our cars the drive shaft pushes more into the transmission which causes stress on the bearings

[datzenmike]

The differential is fixed to the frame in an IRS 510. Lower it all you like the differential / drive shaft does not get closer to the transmission.

[Scgreen620]

I have a truck I forgot that might be my problem

[datzenmike]

It happens all the time.

[Stoffregen Motorsports]

Check the bearings I'm having the same problem too.. I over hauled mine a year and a half ago and it's doing the same thing again

 

A guy told me it might be the drive shaft being too long since we lower our cars the drive shaft pushes more into the transmission which causes stress on the bearings

It only causes stress on the bearings if it's bottoming out on the trans. The only way to measure for sure is to cycle the suspension with the driveshaft in, but that's not very easy to do with a leaf spring suspension. The other way to get close, is to take the driveshaft out and measure from the tip of the output shaft (transmission) to the middle of the flange on the diff. Take that measurement and your driveline to a driveline shop and ask their opinion.

[Scgreen620]

It only causes stress on the bearings if it's bottoming out on the trans. The only way to measure for sure is to cycle the suspension with the driveshaft in, but that's not very easy to do with a leaf spring suspension. The other way to get close, is to take the driveshaft out and measure from the tip of the output shaft (transmission) to the middle of the flange on the diff. Take that measurement and your driveline to a driveline shop and ask their opinion.

 

From the way my truck sits the drive shaft is almost straight .. Im guesstimating that when I hit a pot hole or something the drive shaft gets pushed in a bit

[Stoffregen Motorsports]

Do you mean to say that the height from the ground to the pinion flange is the same as the distance from the ground to the tailshaft?

 

The shortest distance between two points is a straight line.

[Scgreen620]

It almost is a straight line it has a slight angle but I feel like when I do hit a pot hole it is straight ...