94 5 speed swap slave & master

[JPVortex]

Hey yall, 5 speed swapping my 94 K1500. 99% sure I have a 5LM60 going into it. Has casting gm8672306. This trans would've been in an early 90s truck.

I have one concern though.

Looking for master cylinders and slave cylinders, I'm getting different part numbers for a 90 K1500(around the year of the transmission) and a 94 K1500(the year of the truck the 5lm60 is going into), questions are as followed:

1. Which ones should I purchase? The ones for my year of truck or for the year(I dont know exactly what year the trans came out of) that the transmission came out of?
2. What is actually the difference between them? Are the bore lengths or rod lengths different or something? Always just thought if it was an external slave it would have the same part number, but everywhere I look has different part numbers for the different years.

Thanks!

 

[someotherguy]

88-94 share the same bolt diagonal pattern on the firewall so that's not the difference, it might *maybe* be a difference of metal vs. plastic m/c? Beats me. I haven't worked with a lot of different light 5 speed trucks so I haven't noticed a lot of differences in them.

I'd say since the m/c bolt pattern is the same on the early interior trucks, stick with the part # that matches closest with the transmission you chose, is probably the best bet, but if you can, wait until someone who may have already traveled down this path has better advice.

Richard

 

[JPVortex]

88-94 share the same bolt diagonal pattern on the firewall so that's not the difference, it might *maybe* be a difference of metal vs. plastic m/c? Beats me. I haven't worked with a lot of different light 5 speed trucks so I haven't noticed a lot of differences in them.

I'd say since the m/c bolt pattern is the same on the early interior trucks, stick with the part # that matches closest with the transmission you chose, is probably the best bet, but if you can, wait until someone who may have already traveled down this path has better advice.

Richard

I found the difference in the slave cylinder. The location where the clutch line goes in is different. On an early one for a 1990 it goes in the side, on a 1994 it goes in at the back of the slave.

I’ve heard bleeding these systems can really suck so I want to get something prebled, but can only find a prebled master, slave and line for a 94, not a 90. So I may just send it, try it and see if it works.

 

[Erik the Awful]

Are you trying to keep your truck original, or is there a physical limitation that requires use of a side fitting? Asking because I have a later pre-filled clutch hydraulic sitting in the corner with an NV3500 that might go in a truck at some point.

 

[JPVortex]

Are you trying to keep your truck original, or is there a physical limitation that requires use of a side fitting? Asking because I have a later pre-filled clutch hydraulic sitting in the corner with an NV3500 that might go in a truck at some point.

I don’t need the side fitting, actually prefer it on the end, was just worried that the 2 styles would have a different length slave cylinder rod or something.

All the prebled ones are for a 94, with the end fitting which I like more, was just a bit worried about it because the 5lm60 I’m putting in is out of a 90 or a 91. But aslong as the rod length is the same I think it’ll be okay.

 

[JPVortex]

Side note, do y’all think I made a big enough hole for the shifter to come through? The boot ID measured 5.25 inches by 5.25 inches, I cut mine 5”x5”.

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[someotherguy]

Side note, do y’all think I made a big enough hole for the shifter to come through? The boot ID measured 5.25 inches by 5.25 inches, I cut mine 5”x5”.

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Probably. The light duty 5 speed should fit without much issue; I imagine the toploader NV4500 needs more space and this is the factory cut:

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Richard

 

[Piratehunter]

I’ve heard bleeding these systems can really suck so I want to get something prebled, but can only find a prebled master, slave and line for a 94, not a 90. So I may just send it, try it and see if it works

mine is a ‘97 with the nv4500. I had read about it being a pain to bleed, but when I installed a new slave, I just cracked the valve open and it gravity bled from the master just fine.

 

[JPVortex]

Probably. The light duty 5 speed should fit without much issue; I imagine the toploader NV4500 needs more space and this is the factory cut:

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Richard

Oh yeah, mine will probably fit right in there.

 

[JPVortex]

mine is a ‘97 with the nv4500. I had read about it being a pain to bleed, but when I installed a new slave, I just cracked the valve open and it gravity bled from the master just fine.

Did you bench bleed the master at all? Or no need?