75 280Z - 5 speed swap from 81 280ZX - any catches I should be aware of?

[HusseinHolland]

So, question for those who've removed the trans- can you disconnect the shifter at the base from beneath the car, one video I saw it appeared that he just lowered the back of the tranny, and then disconnected the shifter from underneath rather than removing the entire console. Is that in fact the case? Would make life easier for sure. If anyone can confirm that that would be great.

[Zed Head]

Seems possible if you can work in that tight space.  It might even be easier to get the pin aligned and the circlip on.  Worth a shot.  Worst case you just do what you were trying to avoid.  Wish I had thought of that.  I hated removing my console, Nissan made the wires so short it was really a pain to work with them.

[Dave WM]

yes, its rather easy actually. just once you get the pin out make sure you pull the shifter up and out of the way, it will flop around some but no big deal. You want to avoid having it drop down and get in the way when pulling the trans back off the block. 

Do note the way the pin goes in, IIRC its inserted from the left side, and has a flat that needs to mate up on the trans housing when reinstalling. Oh and watch that circlip, it will jump out and get lost if you are not ready for it. 

[Dave WM]

just to clarify the ease part, IIRC after removing all the drive shaft stuff so you can clearly see the tunnel, use a trans jack to support and then remove the rear mount. lower the trans (best to have removed the rad or at least have someone keep an eye on it so as the engine tilts back you do not have a fan blade dig into the rad core), until you can clearly see the shifter pin. You will have enough room to get in there with a pick and remove the circlip, pull the pin, pull up from the inside of the car the shifter, and get it secured so it does not impede the rest of the work. 

installing a trans with the engine in is a hit or miss prob as far as the hassle of getting the input spline to align with the clutch plate. I like to use some long bolts with the heads cut off as guide pins (I cut slots in the top to allow for a screw driver to be use to remove the bolt once trans is fitted), one on the top and one on the bottom opposite side. This lets you get the trans clocked right and in the general position. from there it's a lot of wiggle, push, swear words, then pop it just goes in. Sometimes you get lucky and it just goes in and you wonder what everybody it talking about it being a PITA.

A tip is to put the trans in gear before removing the shifter, this will allow you to twist the output shaft by hand while doing the wiggle/push motion. The idea being IF your spline is just off a hair it may help it align. In reality the guide pins should be sloppy enough to let you twist the entire trans, but if the input shaft is binding up on the clutch and not in the perfect position it may resist moving to align. Being in gear gives you a bit more control over the ablity to align the input shaft. 

another tip, when tightening the pressure plate make darn sure the clutch alignment tool is going in straight. I can droop a bit from the weight of the friction plate. You should try to aim for a neutral position between the up and down amount of play even with the tool installed. Make sure as you go the tool can be inserted and removed easy.

I have done this a few times, like I said sometimes it just pops in so easy you wonder what is the big deal, other times not so much.

last tip, make sure the alignment dowels are in place, these keep the trans input shaft perfectly centered, there are 2 diag mounted I cant recall if they go in the block or the trans housing. The fit OVER the bolts in enlarged holes, so the bolts go thru them. 

 

 

 

 

 

Edited June 5 by Dave WM

[HusseinHolland]

I ordered 2 quarts of the GM 10-4014 Friction Modified Synchromesh - now I can't find the the thread where fluid options were discussed - I know I ordered it for a reason. EDIT - chickenman mentions it here

@Dave WM - thank you - I'll make guide dowels. A similar issue happens with the Fiat X1/9 transaxle where the input shaft splines can be a bitch to engage/align, a similar approach with guide pins is used there also. I'm just gong to print you post, so I have it on hand for reference.

Had fun getting the rear casing back on today, after replacing the shaft seal & housing oring

I had to watch through the reverse check sleeve hole to see if I was getting the 'striking lever' into the fork slot. Took a bit of back & forth & up & down to get it in place. Couldn't photograph it clearly

Mopar transaxle casing RTV- since I had it on hand, I decided to use it

casing bolts cross-pattern torqued to 13ft/lb

Used Honda clutch shaft grease for the T/O sleeve, fork pivot & shaft splines

Noted that the Loctite I'm using is 592, not the 567 otherwise mentioned. I'll have to look that one up.

 

Also need to figure out the speedo gear - I think the normal route is to swap the existing one over - but.... mine isn't accurate anyway (with the 15" wheels and tires it's over by more than 10% by 65 (displayed) and goes up from there. I'm wondering if this one will possibly bring it closer? Have to research that.

 

 

 

 

 

 

Edited June 6 by HusseinHolland

[Zed Head]

This page might help on the speedo gear.  

https://www.thezstore.com/category/1005/speedometer-pinion-parts

[Yarb]

At one time IIRC there was a chart here that showed trans/gear ratio to the color of the wheel itself. Getting old but I do remember something to that effect.

[HusseinHolland]

I'll count the teeth on the 75 one when I pull it - according to the linked page the white one I have is 19 teeth. Hopefully mine has only one or two more  teeth than that, which in combination with the 5 speed drive gear should slow the speedo cable enough to make it more accurate at highway speeds. 

 Wife & I tested positive for COVID at the local doc-in-abox this morning - we've been playing tag with whatever virus I got at school for the past 2 weeks, but she is in much worse shape than I. So, not much getting done car-wise, just don't have the energy. 😞

EDIT - found this - so I may as well leave the 19 tooth in, as it has 2 more teeth than the black one in my 75 with 3.54 FD

Edited June 7 by HusseinHolland

[HusseinHolland]

Finally got to pulling the transmission. Removed the fan clutch/blade, and disconnected the throttle linkage at the firewall.

Removed the 2 upper bell housing bolts, and removed the starter motor

Removed the front exhaust pipe and heat shield.

Manual doesn't say to remove the rear swaybar, however there is no access to the driveshaft flange nuts with it in place

angle is all wrong, until I dropped the sway bar.

Made guide pins to ease the re-install . M10x1.5 threads

cut a screwdriver slot in the ends

got the shifter pin/clip out

cleaned up the area where I had pounded the tunnel to fit the 350Z seat

Tranny jack in place

Out. Took some leverage between the bell housing & engine to free it.

I'm gonna say the last tech to work on it (new clutch at some point) was not happy with putting back the worn trans

Only one sleeve guide on the lower left

guide pin on the upper right

 

Found that the relatively new caster rod rubber bushings are already toast. Other side is the same

Also found the forward U Joint is binding - it doesn't look like it is serviceable. Have to look into that

I didn't note which way round this was installed - has two notches on one side

 

 

 

 

Edited July 2 by HusseinHolland

[Zed Head]

Your propeller shaft (Nissan word) has the wrong bolts.  They should be "D" head bolts that seat against the inner yoke surface.  You can see the flat in the picture.  The bolts are still available, it looks like.

https://www.carpartsmanual.com/datsun/Z-1969-1978/power-train/propeller-shaft

The rod is called a compression rod.  It stops the control arm from moving back on braking.  Some people call it the TC rod since it is also in tension under reverse braking.

Nissan started staking the propeller shaft u-joints in 1974 I think.  When the "big body" came around.  You can see the stake impressions in your picture.

 

Just some minor details...

Edited July 2 by Zed Head

[HusseinHolland]

46 minutes ago, Zed Head said:

Your propeller shaft (Nissan word) has the wrong bolts.  They should be "D" head bolts that seat against the inner yoke surface.  You can see the flat in the picture.  The bolts are still available, it looks like.https://www.carpartsmanual.com/datsun/Z-1969-1978/power-train/propeller-shaft

The rod is called a compression rod.  It stops the control arm from moving back on braking.  Some people call it the TC rod since it is also in tension under reverse braking.

Nissan started staking the propeller shaft u-joints in 1974 I think.  When the "big body" came around.  You can see the stake impressions in your picture.

Just some minor details...

Interesting. The bolts in there do seat against the flange lip - there is no way to rotate the bolt. Perhaps they swapped out the factory bolts when they did the clutch at some point in it's life.

Couldn't recall the Datsun name for the part - Volvo used a similar design, just called it a caster rod, since it affects the caster  🙂

I've found that Rockport 430-10 is the replacement U-Joint, I just ordered the Dana version off RockAuto as it will get here much quicker than the other options I could find. Apparently the replacements use a C clip that locates on the insides of the yoke, rather than the traditional clip in a groove on the outside of the cap. Stakes have to be removed first, of course.

 

 

Edited July 2 by HusseinHolland

[Zed Head]

There's quite a bit around the old internet about converting the staked joints to clipped in.  I recall mixed results.  Since Nissan wasn't using that inner surface for the clip to seat against it's likely that they did not machine it to a tight tolerance.  Just a guess.  Might have fit or balance problems.  Worth a shot.

The switch point seems to be November 74.  So it's 1975 model year and on.

https://www.carpartsmanual.com/datsun/Z-1969-1978/power-train/propeller-shaft/6