LD20 turbo wagon build

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510tdi
Posts: 133
Joined: 05 May 2013 19:44
Location: Troutdale (near Portland) ,Oregon

Re: LD20 turbo wagon build

Post by 510tdi » 31 Jul 2015 17:27

Hi Jon,
I'm assuming you've found some hinge pins by now but if not, I'd still be happy to help out. Hope things are going well with the project. When do you anticipate getting the body back?

Bryan

510tdi
Posts: 133
Joined: 05 May 2013 19:44
Location: Troutdale (near Portland) ,Oregon

Re: LD20 turbo wagon build

Post by 510tdi » 31 Jul 2015 17:31

Oops,
Sorry about the(almost) duplicate message.

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MikeY
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Location: Qualicum Van Isle

Re: LD20 turbo wagon build

Post by MikeY » 31 Jul 2015 18:28

He will still need the pins. I assume he will chime in soon. Ive started the car and its going well. I have stripped most of the paint and sandblasted the engine compartment. Now the welding begins. Not a huge task on this shell. 5 or 6 patches and both rockers. I figure a couple of months. I'd add some pictures but I only have my phone and have not figured out an easy way to resize them.

jon510
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Re: LD20 turbo wagon build

Post by jon510 » 15 Sep 2015 11:07

The wagon is moving along. Mike is making good progress and most of the rot is out and new steel is in. I'm having some trouble uploading photos from my phone but I'll try to get them on here shortly. It looks like I better stop procrastinating and choose a color in the next few weeks as the paint will likely be going on in October sometime. I just got all my seals from datsport, along with their seatbelts with the dropped shoulder harness which will fix one of the things have have bugged me in all my 510s. Still need to order a headliner, carpet, and few bits for the engine....

I have been playing around with the sticky mess of wires that is my unwrapped engine wiring harness. I'm going to try to delete the starter and backup lamp relays, although even with a good wiring diagram I'm a bit perplexed. I've posted elsewhere on this, so if anyone has done the auto--> manual conversion and removed all the redundant relays, I'm all ears. See viewtopic.php?f=32&t=28364 . Otherwise I will try to do it when the harness is back on the car, I can't test it at present. I will get all the new glow plug/fuel solenoid/fuel pump wiring incorporated into the harness as I clean things up.

I'm also playing around with the new zx tranny and clutch setup. The good news is that the zx transmission has an input shaft that's about 1/2" shorter than the dogleg was, so no cutting required to fit it. The problem I'm having is the clutch TO bearing sleeve length. Previously, the sleeve I had measured almost 10mm short based on the 'magic number' others have given me for the total length of the bearing sleeve tabs (where the fork sits) to the flywheel. See this post:viewtopic.php?f=30&t=27619

When I used the collar that I pulled off my dogleg/L16 combo, my overall measurement was 79mm (flywheel surface to the ears on the sleeve). Unfortunately when installed, the clutch fork sat pushed back very close to the slave cylinder, allowing no adjustment to it. The slave pushrod may even have been engaging the clutch slightly when installed, I'm not quite sure. Anyway, the clutch slipped when driving regardless.
fork original.jpg
fork original.jpg (51.72 KiB) Viewed 1481 times
Trying to work my brain around this, it seems that if the fork is pushed back right towards the slave cylinder and there's no play in the fork, the TO bearing sleeve must be too long. With a shorter sleeve, I assume there would be more play between the bearing and PP so the fork could move away from the slave cylinder without engaging the clutch. At least, this is what my non-mechanically inclined brain thinks. I don't have a shorter sleeve at present, but I did order a '240sx' sleeve/bearing combo from rock auto, thinking this would work since it's a 240sx clutch. This ends up being about the same overall length as the setup I tried previously.

Since the measurements I have are still shorter than 89mm, I had a go with a sleeve that is about 5mm longer in case my brain isn't working this through correctly. Then I can't bolt the slave cylinder on.
fork tranny 2.jpg
fork tranny 2.jpg (76.26 KiB) Viewed 1481 times
So, I'm thinking I need a short collar. But then my length measurements will be way less than the 89-92mm number everyone quotes. So I'm wondering if I've done something else wrong (can't see what it would be, clutch disc is installed in the right position, etc). I'm wary of just throwing a shorter sleeve on and bolting everything up since if it's wrong once I get it in the car it's a pain to pull apart again. I'm using the stock 510 slave cylinder, I don't think using a zx unit would make a difference, but I could be wrong I suppose.

Thoughts? Thanks,

Jon

510tdi
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Re: LD20 turbo wagon build

Post by 510tdi » 15 Sep 2015 22:55

Thanks for the update Jon. Details, details, details! It seems like you're thinking right to me but it's been many years since I pulled a 510 tranny and engine. Good luck!

Bryan

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Byron510
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Re: LD20 turbo wagon build

Post by Byron510 » 16 Sep 2015 06:51

Hi Jon, I would agree that you do need a shorter collar to position the fork well. If the clutch is slipping already, then there is certainly something not right. There needed to be at least a couple mm free play on the fork at all times, if the free play isn't there, then the TO bearing is riding on the pressure plate.
If there is a tiny amount of free play, then there might be another issue.
Keep us posted.

Byron
Love people and use things,
because the opposite never works.

jon510
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Re: LD20 turbo wagon build

Post by jon510 » 16 Sep 2015 08:14

Thanks Byron.

I dragged James over to look at the setup yesterday and we brainstormed a bit. We threw the bearing/collar assembly up against the installed flywheel. Measurement was 81mm to the tabs on the sleeve ears where the fork sits. So according to the measurement it's short, but it's almost identical to what came out of the dogleg/L16 and worked. I can't quite think of what other variable would affect the play of the TO bearing besides the collar length, but it's making me wonder if I've done something else wrong. I took the PP off and had a look the other day, it seems to be installed in the right direction so it's not that.

I'm going to have a go at taking the fork off and installing the tranny next, maybe I can see through the fork window how tight the bearing is to the PP and make sure that's actually the issue. I'll try to find another shorter collar and see if that works, I'm just a little worried that given my measurements I'll get the fork in the right position, but it won't engage the clutch fully when installed.....

Jon

jon510
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Re: LD20 turbo wagon build

Post by jon510 » 18 Sep 2015 08:53

I had another look last night. After pulling out the clutch fork, I can see there are only a few mm of clearance between the splines on the PP and the TO bearing. With the fork reinstalled, there basically is no clearance. I'm assuming that this put a little pressure on the splines when installed before, or that the slave cylinder always held a bit of pressure on the fork causing the slipping issues I had.

I've been mulling over why my measurements don't jive with what I've been told. The only thing I can think of is that the flywheel is about a 1/2" thicker on the LD, none of the advice I received before said anything about this measurement but looking at it, this must push everything closer together within the bellhousing making the clearances much less.

Anyway, I guess I will source another shorter sleeve and hope that it will all work when installed.

Now on to removing the pan and potentially notching it for my sway bar.

Jon

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James
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Re: LD20 turbo wagon build

Post by James » 18 Sep 2015 11:22

Jon -
Just a side note on this -
A long time ago on one of my first adventures into a clutch install, I had pressed the throw out bearing onto the collar backwards (seems insane now) and it changed the clearance enough that the clutch would be dis engaged when resting…..
Just another potential thing to check (I only figured it out after having the tranny in and out 4 times….)
Good Luck
James
Finished is better than perfect......

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Byron510
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Re: LD20 turbo wagon build

Post by Byron510 » 26 Sep 2015 06:50

Jon, have you learned anything further on this clutch issue?

Byron
Love people and use things,
because the opposite never works.

jon510
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Re: LD20 turbo wagon build

Post by jon510 » 26 Sep 2015 08:48

No, I'm a bit stuck. As I mentioned, I think the clearance issue is due to the thick flywheel, this makes sense in my brain at least as the other measurements are virtually identical between the prior clutch setup and the new one. I spoke to Robyn yesterday to see if I could find a short collar to test out. He doesn't have any kicking around but he told me the shortest version is from the roadster. I see on datsunparts.com they have two of these that are short so I'm probably going to order one and will hope that it fits. I'm not sure if it's possible to be too short, I hope not given my situation but am not sure how to guess best on measurements. The two are very similar in length for the roadster 4 and 5 speeds (0.818 and 0.975" is what they emailed me to the flange where the bearing sits) - the 5 speed (0.975) looks to correspond to the 38.5mm unit which is the shortest listed that I've found ( http://community.ratsun.net/topic/58641 ... selection/ ). It may be worth it to order both units in case this is still too long. The only other option would be change out the flywheel for something else for a 225mm clutch, but I gather I probably want the heavy unit that's on there for the diesel.

I was hoping to make it out for the drive Sunday but it's not in the cards, I have to work and have a brunch to be before - have fun!

Jon

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James
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Re: LD20 turbo wagon build

Post by James » 26 Sep 2015 14:22

Thick flywheel - doesn't necessarily compute in my head - unless it was machined improperly. If it were machined - the clutch mounting surface and mating surface should be done at the same time. The only way you could end up with too little clearance is if the mounting surface were machined more than the friction surface.
Finished is better than perfect......

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James
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Re: LD20 turbo wagon build

Post by James » 26 Sep 2015 14:24

Also - did you use the clutch fork from the z or the one you had on the dogleg. There are differences in them (I have three different types in my odd stash of things….)
Finished is better than perfect......

jon510
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Re: LD20 turbo wagon build

Post by jon510 » 27 Sep 2015 18:22

The fork is the same as the one I had in the dogleg.

The way I'm rationalizing the flywheel being an issue is that there's only so much room within the bell housing for the clutch parts and flywheel. The bell housing bolts to the block, and the flywheel sticks out From the block. So given there is 0.5-0.75" more flywheel within the bell housing , there's less clearance between the pressure plate and the collar and TO bearing. I've never seen this factored in before to the calculations given, but maybe the diesel flywheel is just way bigger and heavier given the diesel application and the rest of the l series flywheels are closer in thickness? Other than that, there is nothing else in my measurements that has changed between the old and new clutches give or take a couple mm.

I'll try to snap a couple shots to show what I mean. Hope the drive today was good, great day for it.+

Jon

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James
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Re: LD20 turbo wagon build

Post by James » 27 Sep 2015 22:09

I see what you are saying - the thickness of the flywheel is altering the distance to the pivot of the fork.
Finished is better than perfect......

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