Jump to content


Photo

PressurePlate auto vs Manual Swap


  • Please log in to reply
12 replies to this topic

#1 Kathos

Kathos

    Advanced Member

  • Members
  • PipPipPip
  • 93 posts
  • Location:Pittsburgh
  • Cars:710 Datsun

Posted 24 May 2017 - 04:00 AM

So I almost had the Datsun on the road for the summer after dealing with a coolant system nightmare. I go to drive it out of the garage. Starts up fine. I shut it off while I move other obstructions out of the way. When I go to start it again, it wont start. I can hear the starter, but nothing else.

I take off the starter to see that the teeth pressure plate are eaten in that particular spot.

 

So now I am stuck banging my head because I have plenty of other projects going on. What is the involvement of swapping out the pressure plate? Does the transmission need to be pulled?

Id rather have a manual, should I just hold off and collect parts to do the swap? Id obviously rather the 5speed, but so does everyone else. So a 4speed might be more realistic.

 

If anyone has either of these, let me know.



#2 datzenmike

datzenmike

    KING RAT

  • User Administrator
  • 70,349 posts
  • Location:Vancouver Island
  • Cars:'74 710 sedan, '76 710. prevoius... '78 620, '71 521, '68 510 new '76 B-210

Posted 24 May 2017 - 04:51 AM

Yes automatic needs to come out to get at this.

 

 

71B 4 or 5 speed swap in addition to the pedals you need...

 

http://community.rat...n/#entry1490746

 

 

 

The dogleg transmission from a '77-'79 S10 200sx is the same length as your auto so no driveshaft shortening. I would still recommend the 71B as they are stronger and easier to find.


Posted Image

#3 flatcat19

flatcat19

    Back in Black

  • Senior Member
  • PipPipPipPipPipPipPipPipPipPip
  • 19,979 posts
  • Location:Tri-Cities, WA/PDX
  • Cars:Smaller. Better. Slower. Lower.

Posted 24 May 2017 - 05:40 AM

Pressure plate is what holds a clutch disc to a flywheel.


Flex plate(automatic transmissions) holds the torque converter.

You can't hang if your nuts haven't dropped...it's physics


#4 Kathos

Kathos

    Advanced Member

  • Members
  • PipPipPip
  • 93 posts
  • Location:Pittsburgh
  • Cars:710 Datsun

Posted 24 May 2017 - 09:11 AM

Thanks for correcting me. A flex plate is indeed what I need.

Ive never done a transmission swap and from the research I've done, pretty much every post has been information from you so thanks both of you.

What do you mean by 71B? Is that the longer transmission that requires a 5.5" shorter driveshaft?

For the Flex plate, is it a pain to put a new one in? Id imagine its just unattaching the driveshaft, remove the couple bolts holding the bell housing, removing the transmission and unbolting the flex plate?



#5 flatcat19

flatcat19

    Back in Black

  • Senior Member
  • PipPipPipPipPipPipPipPipPipPip
  • 19,979 posts
  • Location:Tri-Cities, WA/PDX
  • Cars:Smaller. Better. Slower. Lower.

Posted 24 May 2017 - 10:38 AM

Remove transmission, remove bolts. That's all it is.


Dependant on the length of your current trans vs. length of new one will decide what, if anything, needs to be do e with your driveline.


The 71B is probably the most common manual trans found in L and Z series motors.
Mike would be better at all of those details than I.

Given your location, hunting parts is going to a lot harder for you.

You can't hang if your nuts haven't dropped...it's physics


#6 Kathos

Kathos

    Advanced Member

  • Members
  • PipPipPip
  • 93 posts
  • Location:Pittsburgh
  • Cars:710 Datsun

Posted 25 May 2017 - 02:51 AM

There is currently a 620 4speed for sale around me. Its a rusty mess but its close. Its a 74 though.

https://pittsburgh.c...6124393106.html

If its compatible. Ill ask if hes interested in parting it out.



#7 Kathos

Kathos

    Advanced Member

  • Members
  • PipPipPip
  • 93 posts
  • Location:Pittsburgh
  • Cars:710 Datsun

Posted 25 May 2017 - 04:54 AM

I also may go this route. I don't know if anything else has been done since, but flipping the ring gear might be an option. Or buying one brand new.

 

 

'74 710 L18 starter ring gear is 12312-A8600 and about $100 at dealer. It was used on all L4 and L6 automatics and standards through the Z24i in the D21 and WD21. You could easilt tap the one off a standard flywheel... cut yours off at the welds and have someone weld it back on.

About $160 for the 5 bolt flex plate assy from dealer.


Cheaper to find an auto flexplate from a '71 and up 510, early L16/L18 620, 610 or 710 automatic.



#8 datzenmike

datzenmike

    KING RAT

  • User Administrator
  • 70,349 posts
  • Location:Vancouver Island
  • Cars:'74 710 sedan, '76 710. prevoius... '78 620, '71 521, '68 510 new '76 B-210

Posted 25 May 2017 - 05:07 AM

I also may go this route. I don't know if anything else has been done since, but flipping the ring gear might be an option. Or buying one brand new.


This works if only the leading wdge is worn by the starter. If the gear is totally worn away as you say yours wasn't engaging at all, this won't help.

 

There is currently a 620 4speed for sale around me. Its a rusty mess but its close. Its a 74 though.
https://pittsburgh.c...6124393106.html
If its compatible. Ill ask if hes interested in parting it out.

 
I have a 71B 5 speed (same length as the 4 speed) in my 710. I used an automatic drive shaft they are the same length. 

 

You will need  http://community.rat...n/#entry1490746


Posted Image

#9 Kathos

Kathos

    Advanced Member

  • Members
  • PipPipPip
  • 93 posts
  • Location:Pittsburgh
  • Cars:710 Datsun

Posted 25 May 2017 - 10:35 AM

Thanks for the information. From what I found out, the early 620 automatics were actually the 31" and the 620 manuals were 26", the same length as my automatic.

Mike, I'm pretty sure you answered this before, but do you know how many teeth the starter gear has? I thought I read it had 131 but I was referred to this one which only has 120. I don't want to order the wrong thing.



#10 datzenmike

datzenmike

    KING RAT

  • User Administrator
  • 70,349 posts
  • Location:Vancouver Island
  • Cars:'74 710 sedan, '76 710. prevoius... '78 620, '71 521, '68 510 new '76 B-210

Posted 25 May 2017 - 11:31 AM

Automatics were 31.5", the '73620  4 speed was 26" then changed to the 31.5" long 71B in '74.

 

Teeth, I'd have to go count one. Count yours.

 

Automatic and standard flywheel starter rings are the same. Autos are welded on. Standards, the flywheel is placed in the freezer over night and the ring heated in the oven to 400Fthen assembled..  


Posted Image

#11 Doctor510

Doctor510

    Senior Member

  • Senior Member
  • PipPipPipPip
  • 661 posts
  • Location:Mesa, AZ
  • Cars:Many 510's

Posted 25 May 2017 - 03:23 PM

Is your motor an L16 or 18? Or s it an L20b?



#12 Kathos

Kathos

    Advanced Member

  • Members
  • PipPipPip
  • 93 posts
  • Location:Pittsburgh
  • Cars:710 Datsun

Posted 25 May 2017 - 04:14 PM

Will do datzen mike.
Doctor510 its a L20b.

#13 datzenmike

datzenmike

    KING RAT

  • User Administrator
  • 70,349 posts
  • Location:Vancouver Island
  • Cars:'74 710 sedan, '76 710. prevoius... '78 620, '71 521, '68 510 new '76 B-210

Posted 25 May 2017 - 04:30 PM

So you need a 6 bolt hole flex plate. Any L20B or 240/260 280z or 280zx, 810 should work.


Posted Image