Transmission hard to get in gear

[jbow03]

I have a T5 bolted to a 302. Hydraulic clutch setup with an external slave from Modern Drive Line with the kit Wildwood from FFR.

Had first go kart yesterday (woohoo!) but I struggled to get the transmission in gear, reverse or first.

I feel good about the bleed, no "dead" zone and good motion from top to bottom of the stroke. But it feels like I need to push the clutch through the firewall to get close to being able to get it in gear and the car starts to slightly roll before falling into first. I feel like it needs more stroke on the back end but not sure what to do to get it.

I have heard about bore size ratio and what not, but hadn't gone down that rabbit hole as I hope I resolve it with the gear I've bought.

Is there adjustments that need to be made somewhere to get more "action" out of the clutch?

Here's the kit from MDL: https://www.moderndriveline.com/shop/mdl-lf-series-external-hydraulic-slave-kit-ford-t5-transmission-mounted/

[michael everson]

Start by making sure all of the free play is out of the push rod. Can you move the pedal up a bit by adjusting the threaded rod on the master?
Mike

[jbow03]

Probably, I had adjusted it to be a bit above the brake pedal but I'll try to get it higher tonight.

[Dgc333]

I have an internal hydraulic throwout bearing so nothing to adjust down there other than setting the initial clearance between the bearing and the fingers on the clutch.

I had the same issue the first time I tried to put mine in gear with the engine running. I turned the MC pushrod out of the clevise (makes the pedal higher) on the pedal box in 1/2 turn increments until I could put it in gear with the engine running then added another 1/2 turn. Got 2k miles on the car now and the clutch has been perfect.

If you want to keep the pedal low swap the MC for one with a bigger bore (7/8" or 1"). Just keep in mind the bigger bore will also increase pedal effort.

[Mike.Bray]

It's very important to have the correct size master cylinder (and one that's not leaking or bypassing fluid). Don't assume what you have is correct. I ended up with a 13/16" bore for the clutch.

[Wizbangdoodle]

I've got the Forte external slave kit and it came with a new master for the clutch. Size is a .81. As mentioned, larger MC more throw, but harder pedal. Also mentioned, adjust the pedal up a bit more. I just went through this adjustment myself. I put a ratchet strap on my clutch fork and moved it forward until it just released. I marked that position on the bellhousing. Then I knew how much stroke I needed and where it needed to get to. This also allowed me to set the gap between the clutch fork and tob. I also had to adjust my pedal up more.

Sounds like you are just about there, just need that last little bit. Good luck.

[CraigS]

I actually like my clutch pedal higher than the brake. I figure the brake pedal may move 3" in use. The clutch may move 5" in use. So I set the height so at least some of that extra 2" of needed movement is closer to me.

[BornWestUSA]

My research said that you need 1.2" of clutch release arm "throw". what does yours measure where the slave mounts?

the bore of the modern driveline clutch slave is approx .75"

What pedal box do you have?

If you have a Wilwood pedal box it has a 6:1 ratio, meaning 6" of pedal travel nets you 1" of master cylinder travel.

So if your master cylinder is .75, and your slave is .75 you need MORE than 6" of pedal travel for proper function.

A larger Master cylinder (13/16) may be needed.

[jbow03]

Thanks for all the input!

I have the Wilwood set from FFR kit. I adjusted the rod and that has helped a ton! I can get in and out of first great, reverse is a little ‘’Grundy’ but not terrible. I just don’t like that the end of the rod has been adjusted so much that I’m now about half way through the pedal end. I guess the jam nut will provide enough positive pressure on the assembly that I won’t lose the connection, but I may be looking at a new MC now that’s a little larger.

What series of MC comes with these kits? I’ve noticed Wilwood has a number of options out there.

[Dgc333]

FFR supplies 3/4" Master Cylinders for the brakes and the clutch.

[Mike.Bray]

If you're going to change out the master cylinder go ahead and upgrade to Tilton. Way too many failures with the Wilwoods.

https://thefactoryfiveforum.com/showthread.php?49560-Swapping-Tilton-MC-for-Wilwood-MC&highlight=tilton

[BornWestUSA]

Thanks for all the input!

I have the Wilwood set from FFR kit. I adjusted the rod and that has helped a ton! I can get in and out of first great, reverse is a little ‘’Grundy’ but not terrible. I just don’t like that the end of the rod has been adjusted so much that I’m now about half way through the pedal end. I guess the jam nut will provide enough positive pressure on the assembly that I won’t lose the connection, but I may be looking at a new MC now that’s a little larger.

What series of MC comes with these kits? I’ve noticed Wilwood has a number of options out there.

I used this one after removing the .7 that the original builder had installed:

https://www.amazon.com/dp/B01M7VOY82?ref_=ppx_hzsearch_conn_dt_b_fed_asin_ti tle_1

[Wizbangdoodle]

If you're going to change out the master cylinder go ahead and upgrade to Tilton. Way too many failures with the Wilwoods.

https://thefactoryfiveforum.com/showthread.php?49560-Swapping-Tilton-MC-for-Wilwood-MC&highlight=tilton

Just curious Mike, what fails with the Wilwoods?

[jbow03]

Wow, I just stumbled into the Wilwood/Tilton MC rabbit hole big time!

Now I have decisions to make while my body is off!!

On the bore size issue, my math shows just going to 13/16 will provide 17% more linear movement at the slave given my setup currently is 3/4 MC and 3/4 SC. That sound right?

[Mike.Bray]

Just curious Mike, what fails with the Wilwoods?

There's a lot of information in this thread. https://thefactoryfiveforum.com/showthread.php?49560-Swapping-Tilton-MC-for-Wilwood-MC&highlight=tilton

Most of the time it's a wear issue with the piston and/or bore. The design is weak, the piston for example and the bore not being hardened. Some failures are manufacturing, fail right out of the box.

By failure the piston loses its seal with the bore and allows fluid to bypass. The clutch usually goes first as it's actuated the most. The scary thing is with the balance bar design for the brakes if one brake cylinder fails it results in total brake failure.

[Blitzboy54]

If you want your clutch to engage sooner in the pedal stroke simply lengthen the piston attached to the slave cylinder. Your released bearing is not quite close enough to the pressure plate fingers. If you’re happy with it carry on but that is/was your issue. You compensated for it by pushing the pedal forward.

[jbow03]

Thanks for jumping in Blitzboy54! This was at the heart of my original question!

When you say "lengthen the piston attached to the slave cylinder", what do you mean? Get a longer threaded adjustment rod and back out the adjusters until I'm happy with it? Can I take that too far? Are there risks in putting pressure on the throw out bearing too soon in the stroke?

[Blitzboy54]

This was my first build. Very similar to yours. 306 with a T5 and an external slave cylinder. What I mean by lengthen the piston is the rod poking out of the (in my case) pink slave cylinder. When you adjust the threaded nut so that it pushes the fork away from the cylinder it is pushing the throw out bearing closer to the pressure plate fingers. Therefor when you push on the pedal it engages the clutch sooner. The closer you are to the pressure plate when you start to engage the clutch the sooner it will release in the pedal stroke. The potential pitfall here is you do not want to over adjust it. If you do that then the clutch will be partially engaged all the time and will slip. It sounds to me like you have a little more room to adjust potentially. A good rule of thumb I like to target mid pedal stroke (half way) for full clutch engagement. If I was racing I would want it near the top of the pedal stroke but for normal everyday usage half way is pretty good.

https://thefactoryfiveforum.com/attachment.php?attachmentid=150179&d=1625178776

[BornWestUSA]

Modern driveline has a good bit of information on clutch hydraulic set up. That is where I found the data point of 1.2" travel is necessary at the clutch slave for proper operation.

The clutch slave should not be applying any pressure on the throw out bearing when your foot is off the clutch pedal, there should be a tiny amount of "free" play on the clutch release lever.

https://www.moderndriveline.com/installation-instructions-for-sbf-t-5-tko-aluminum-bell-external-slave-cylinder/

[jbow03]

Thanks for the recommendations.

I've ordered and installed a Tilton 13/16 unit. Just need to bleed, adjust the slave/fork connection and give it a shot! More details to come...