Hey guys,

I purchased a 93 T100 a few months back, beautiful truck. Recently it started getting harder and harder to get into gear to where now it takes just about all my strength for it to pop in. It seems to have no problem when the truck is off, she slides into gear no problem. When the truck is running is when it becomes next to impossible. Even when it does pop in there’s no grinding. I’ve had a few mechanically inclined friends try and diagnose it. Some say slave cylinder, some say clutch. All my fluid levels seem to be proper. At this point it’s not really road worthy and would be tuff to get to a transmission shop. I’m wondering if anyone has had this same problem. Any tips or ideas would be greatly obliged.

Thank you.

- Mike

 

Your friends are probably right - the hydraulic system attached to your clutch pedal is probably having an issue, could be master, could be slave, could be both. COULD simply need an experienced hand adjusting the clutch. You should have it fixed without driving very much more, it is probably adding wear n tear to the clutch & transmission - if you're straining that hard to shift, it's severe. Hydraulics like master or slave can be pricey but not near as bad as the clutch itself.

 

When it comes to hydraulic clutches there are two things that you will notice when driving, either it slips or it's hard to get in gear.
Slipping is always a sign you need your clutch replaced.
Your problem could be caused by several things, you are helping us a lot by mentioning that it goes into gear fine when the engine is off.
This all boils down to the clutch is not fully disengaging from the flywheel/pressure plate either because the throwout bearing isn't pushing the fingers on the pressure plate far enough or the clutch disc is warped or there is so much oil and gunk on it from a leak that the disc is dragging even when the pressure plate is fully released.
Your first move is to make sure the clutch master cylinder is full and there is no air in the system by bleeding it. check for leaks while you are at it, at the slave cylinder, all along the pressure lines and fittings, and master cylinder including inside the cab where the pushrod comes through the firewall.
If you find no leaks and there is no air in the lines check the fork that moves the throwout bearing looking for signs of bending or cracking or damaged pivot point (or is this a slave cylinder inside the bell housing?)
If you still don't find anything after checking all of that it's time to throw parts at it, but with no signs of leakage I would rule out the slave cylinder and I would only replace the clutch as a last resort. So, throw a master cylinder at it first.
If you DO end up putting in a clutch make sure to get your flywheel resurfaced and inspect the throwout fork and it's pivot ball (here again only if it's an external slave cylinder) for damage or wear.

 

Incredible info akwheeler!

Any chance it would be hard to shift into gear because there is not enough engine oil, like in this post?

https://www.yotatech.com/forums/f132...ifting-311127/

-- Thanks a lot for any quick thought!

 

The answer to your query is No. Not even a slim chance. NO!

Big coincidence, or that guy bumped his head.

 

Ok roger,

I shift about 2000-3000 times a day, city driving.

Today was slick. Yesterday before the add of 1 qt oil, was I almost had to be forceful a couple times getting into first gear. Today, nothing even close. Nothing else changed, except as perhaps a change in outside humidity?

Thunderstorm yesterday, light one today.

 

And last thought is that without the proper level of oil, producing the proper engine compression, the electricals are not activating clutch or synchromesh or something affecting shifting the tranny?

The oil level was at the bottom of the dipstick. I added a quart and now I have no issue at all. Purring along.

Any other factors might we consider?

 

None of that makes much sense to me - I still suspect clutch hydraulic system (throwout bearing can be an issue too). Engine compression shouldn't be much effected by oil being a quart down - oil pressure would be a bit lower - neither of which as far as I know, would affect clutch or syncros.

Here's the only way I see oil level playing a part: being a quart low on oil can mean oil pressure drops a bit - and internal engine temp could rise a bit - so another (I'm guessing here) 5 or 10 degrees F in the lower engine might not show up on the temp gauge but would definitely transfer into the clutch itself & into the hydraulic slave cylinder. And if the hydraulics are weak, the slave could behave differently at a higher temp. So could clutch throw-out bearing - so could syncros in the tranny.

As for outside humidity - I do recall wet or humid weather affecting master & slave cylinders on their last legs, in an ancient '70 Corona which I drove into the ground a few decades back. Which also leads me to say that brake/clutch fluid is funny stuff, it attracts & collects water, and that causes very erratic performance just like you describe. If your fluid hasn't been changed a long time, a flush might be a good idea. Water in the fluid also causes rust in the master & slave cylinder. If your clutch fluid is bad - I'd also change the brake fluid - water there can lead to need to rebuild your brake hydraulics too. "An ounce of prevention" etc.

Let us know what you find! Reminds me of a funny saying... "It may be the main purpose of your life is to serve as a warning to others." We'd like to learn from your experience.

 

Roger on all fronts there,

Seems like a host of options could be the random trouble shifting into first.

Thank you for all the prediagnosis suggestions!

I know when I arrive to a stop and slowly and barely push it into first, it slips in like, well, silk.

Sometimes I think it's just that the gears aren't aligned perfectly at the spot I chose to stop. If I let it roll back or fwd a touch while shifting into first, much easier.

I'll keep a good not and check the fluid you recommender! Thank you!

 

One fairly easy way to tell if your clutch is not disengaging all the way or dragging is to get rolling, and while still in first gear push the clutch, kill the engine, and let it coast. If it feels like your brakes are dragging or comes to a stop like you have your parking brake partially set then you know you have SOME sort of clutch issue. When it's slipping into first while you're slowing to a stop it's because the driveline speed is matching up with the engine speed, and the syncros allow it to pop into gear, even without the clutch. That statement alone tells me the clutch is dragging for one reason or another.