87 clutch master/slave compatability
 

Swapping out the TH400 for a NV4500. I have the 1993 bellhousing with the external slave. Trying to decide if I want to use the 1987 Master/slave and make a custom line, or use the 1993 master/slave that come pre-assembled.
Thoughts or opinions on either setup?

Thanks

Re: 87 clutch master/slave compatability
 

You again! Lol. I swear we're on the same wavelength. I have collected all the pieces of the puzzle to convert the th400 in my 85 to a 93 nv4500. I'm using the AA bell housing and slave bracket. I bought new master cyl/ line & slave off RockAuto for an 85. I'm not sure the 93 will bolt up correctly to the 87 firewall/slave bracket. I have them both and there was a reason I decided to stay with the 85 for some reason.
On another note: Is your engine using the 1 piece rear seal? I realized at the last minute that the new flywheel that came with the trans would not fit the gm crate engine I recently installed due to the 2 piece seal. There are a lot of "gotcha's" in this swap.

Re: 87 clutch master/slave compatability
 

LOL...yep, I'm like a bad rash.

Engine is a 2 piece rear seal. I have the correct flywheel already. I bought a complete 93 trans/bellhousing combo so the slave mounts on the passenger side down low. The 93 master/slave come as an assembled combo with the correct lines. I may need to go with the 80's master and the 90's slave and come up with a line and fittings. I'm trying to figure out as much as I can before I start tearing into it. Did I read correctly that you have both the 80's and 90's master? If so, could you post pics of them next to each other?

Things will really get crazy when I try to swap in a DMax in place of the 454, but that is a story for much later.

Re: 87 clutch master/slave compatability
 

So looking at specs between the 80's and 90's parts, it seems the big difference is the method for attaching the lines. Early are threaded and later are the o-ring style. Looks like bore and stroke are the same for early and later on masters and slaves. In fact, looks like one manufacturer (Luk) installs an adapter in the later model master and has it listed for the early. I think the question is now down to whether I want metal or plastic parts, and if I want to come up with a custom line.

Re: 87 clutch master/slave compatability
 

85-87 have a remote mounted reservoir whereas the 93 is clipped on the slave. Also, the mounting flange is completely different where it mounts to the firewall. Bolt pattern is much smaller on the 93.

If I were you, I'd get a braided stainless hose (-4) and put adapters on each end. Your 87 is probably both metric.

Re: 87 clutch master/slave compatability
 

I forgot the rod tapers UP coming from the mc. That's good cause you need a 7/16 female rod end. Just measured it to verify.

Re: 87 clutch master/slave compatability
 

Great stuff. Thank you. I do have a stock used 80's parts so I can mock it all up.

Interesting that the one I got with my pedal assembly doesn't have the taper - it is uniform diameter all the way through. New master cylinders all appear to have rods with them so I just need to deal with the post on the pedal.

Re: 87 clutch master/slave compatability
 

Just to put more info in one place for anyone doing this conversion later...

The 80's slave cylinder will not work with the 90's bellhousing where the slave is mounted low on the passenger side. The mounting studs on the slave are spaced differently than the holes in the bellhousing. I will be looking at using the 80's master (to match the cab and pedals) and the 90's slave (to match the bellhousing).

Re: 87 clutch master/slave compatability
 

Just to add...the 93 bell housing will only work on 2wd swaps. Otherwise the p/s clutch fork interferes with the front driveshft, that's why I used the AA housing. The AA housing uses a slave cylinder bracket that fits both early/late slaves.

Re: 87 clutch master/slave compatability
 

Next question - AN3 or AN4 for the lines?

Found adapters for the slave from Russell -
641001 for AN4
640281 for AN3

Finding those just solved a major headache. I'm leaning towards the AN3.

Re: 87 clutch master/slave compatability
 

I'd use -3 (3/16th) similar to want the OE lines are. I realized that your slave is on the P/S, thus you'll need a custom line to reach from the master to the slave.

Re: 87 clutch master/slave compatability
 

Yep. That year used those o-ring fittings that you push in then use a roll pin to keep it all together. Those fittings from Russell convert that crazyness to AN so I can make a -3 line and route it however I want.

Re: 87 clutch master/slave compatability
 

Just to help out anyone tackling this conversion in the future -

Russell 640281 to convert the '93 slave cylinder to AN3

Classic Tube SBH8078 to convert the 12mm x 1.0 BBL master cylinder to AN3

Those 2 fittings will allow you to connect the 80's master to the 90's external slave using a AN3 line.