Spicer tranny/clutch

JimSkool

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Joined
Apr 15, 2024
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8
I bought a 2001 international/blue bird 7.3 with a Spicer 5 speed. I've never driven a bus or heavy truck, and to me it feels like it shifts into first/reverse a little hard, and often wants to grind when coming down in gears... This all with the clutch to the floor. It doesn't seem to slip or anything else that I've noticed in the entire 45 minutes I have driven it so far. I was real worried, but now I've seen things that tell me that just may be the way it is. Just looking for some confirmation if I should worry/do some work, or drive it and 😁. Thanks in advance!
 
You've certainly got some wear on those clutches and synchros, so that could be part of it. Check the fluid and let out the clutch pedal a bit.
 
Whoa there, Pilgrim! Don't try to drive that bus another inch -- until we figure out just what you have there.

There are two questions we need to answer about your bus:
1 -- Does it have a Clutch Brake?
2 -- Is that transmission Synchronized?

Me, I have no idea. I have never been near a Spicer 5-speed. But I have 27 years of driving "heavy trucks" -- 18-wheelers -- with 9-speeds, 10-speeds, 13-speeds, and 18-speeds.

Now, about clutch brakes: A clutch brake has nothing at all to do with slowing your travel speed. A clutch brake works to slow down the transmission's input shaft. This makes it easier -- and quieter! -- to engage 1st and reverse.
To use a clutch brake, you push the clutch pedal ALMOST to the floor -- VERY GENTLY, AND ONLY JUST ENOUGH.

(For gear changes while moving, you push the clutch pedal only about half-way down.)

Now, about synchronization: This relates to your grinding between gears, especially when "coming down".
This sounds to me like you have a Non-synchronized transmission. Shifting a non-synchronized transmission requires the fine art of Double-clutching.
It is also possible that you have a synchronized transmission, but that the synchros are worn completely out.

So -- As the most-fortunate owner of a real transmission (as opposed to a !#$%! slush-box), you will now research exactly what you have bought (you lucky so-and-so). :biggrin:


 
It's an '01 5-speed, designed to be driven by mostly amateur "pro" drivers, so I would put money on it being a synchronized-mesh tranny. Even if it is in a Medium-Duty vehicle.


But it's also probably safe to say that the synchros are probably getting soft and trashy, and that double-clutching is a worthwhile learning investment. Hell, the '11 hyundai I sometimes drive has some wear on it, and I still will double-clutch to shift into third or down to fourth, if I'm not skipping third altogether, which is most of the time. Even though I'm pretty sure that both of the squirrels in that engine are tired.
 
I have a spicer 5 speed in my IHC 3800. Drive it like a car. Most likely the clutch is mis adjusted and dragging the disc. Clutch adjusts from in the bell housing. Ask a truck mechanic to take a look at it.
 
Thanks everyone for all the input! Looks like the first thing I'm gonna try is the clutch adjustment. I have a plan to drive it a couple hours, all the way home from where it was purchased. There it will be checked over thoroughly, can be worked on, and happens to be two doors down from a diesel mechanic if I need to call in help. Clutch adjustment where it sits now🙏
 
First gear and reverse are NOT synchronized. You also have to be somewhat patient when shifting-- not like a sports car.

So-- when you are shifting down, you cannot go all the way back to first unless you are stopped.

To get into first or reverse-- sometimes you have to let the clutch out a little to get the gears moving a little before you can get it into those two gears.
 
Porch dog, this sounds like mine feels. And I know not to go in first right away, but I feel like I need to get used to how low 2nd & 3rd gears are compared to a passenger vehicle transmission. Thanks! Still going to look into an adjustment as well. My senses are telling me it might should shift a little better than it does, and maybe it's not as bad as I might have worried
 
Absolutely DO NOT "double clutch", it's synchronized. Drive it like a car or you could damage it.

Don't down shift through gears except to grab a gear (2nd or 3rd) to make a rolling turn. I use 3rd. I have a similar synchro transmission, except mine is a 6 speed model. I do have the Spicer 5 in my retired Ford. You need to reduce your road speed during gear drops. In other words, don't grab 3rd doing 55, grab 3rd doing 18-20MPh or less. When going into reverse or 1st slap the stick into second to synchronize off that hole and then pop back over to reverse or 1st. Then it won't grind, if it does still grind, your clutch disc is hanging up even when released.

Drop the cover on the clutch and grease the throw-out bearing every oil change. Since it's giving you issues, slap some on it now. I'm pretty sure you will have a greaseable throw-out....... could be mistaken and its lifetime lubed. God save the manuals, I love mine.

Good Luck!
 
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Ah, the old days of power shifting, no clutch....
What today's generation will never know.....:whistling:
 
Yup, our new hires are only qualifying for Auto trans. They don't like the challenge. I'm the mechanic and only one of three people who work for this company who can legally drive a stick in a Class 8 truck. Manuals are going away forever. Autos give the machine control over the driver's good/bad habits.
Companies want them.
 


Me, I have no idea. I have never been near a Spicer 5-speed. But I have 27 years of driving "heavy trucks" -- 18-wheelers -- with 9-speeds, 10-speeds, 13-speeds, and 18-speeds.



Back around 1989-1990 I worked for a small towing company in Salinas ca., and they had an old logging truck that was converted into a HD wrecker (Holmes 750 with a hydraulic boom). the neet thing about this truck is that it had a 13 speed road ranger with a 4 speed brownie behind it. That's 52 forward gears and 13 in reverse!

It was built for pulling D8 cats out of the mud and also for tractors that got stuck going up the Laguna Seca racetrack mountain road.

damn thing could do 60 mph in Reverse!
 
kAnk5wq.jpg



General purpose anti theft device.
 
Absolutely DO NOT "double clutch", it's synchronized. Drive it like a car or you could damage it.

Don't down shift through gears except to grab a gear (2nd or 3rd) to make a rolling turn. I use 3rd. I have a similar synchro transmission, except mine is a 6 speed model. I do have the Spicer 5 in my retired Ford. You need to reduce your road speed during gear drops. In other words, don't grab 3rd doing 55, grab 3rd doing 18-20MPh or less. When going into reverse or 1st slap the stick into second to synchronize off that hole and then pop back over to reverse or 1st. Then it won't grind, if it does still grind, your clutch disc is hanging up even when released.

Drop the cover on the clutch and grease the throw-out bearing every oil change. Since it's giving you issues, slap some on it now. I'm pretty sure you will have a greaseable throw-out....... could be mistaken and its lifetime lubed. God save the manuals, I love mine.

Good Luck!


DONT FLOAT a synchro trans.. ive seen more than one spicer medium duty that was destroyed inside.. well the synchros were GONE.. because the driver assumed it was a "truck" transmission and shifted with no clutch.. of course they seemed like big boys floating their gears because the poor synchros were trying to do their job and got destroyed..
 
Spicer

I have a synchronized Spicer 7 speed and it shifts slow and hard but it only has about 10,000 on a complete rebuild so it's stiff. There is almost no downshifting until at a complete stop. Also the gates are so close it's hard to find gears. Sidebar: I was really having trouble finding gears right after I bought it and figured out the gearshift handle set screws were not tightened so it was swiveling right and left as I was trying to find a gear.....impossible!
 
Generally a test I perform in non synconised 9-13-18 speed or whatever else transmissions.......never worked on 5 speeds.....but in this case 1st and reverse could be non synchronized with reverse being almost certain.

To test clutch brake(in this case if equiped) Engine running, press pedal down to floor. Try to select 1st or reverse gear. If it grinds the clutch brake is either damaged, missing, wornout or out of adjustment.

To test clutch operation for blown out disc. dampner springs, siezed pilot bearing or clutch adjustment. Turn engine off, push clutch pedal to floor. Start engine and try selecting 1st or reverse gear. If gear ginds while clutch pedal is to the floor, you the have one of the above conditions of failed clutch disc sprungs, siezed pilot beating or bad adjustment.

Typical clutch adjustment with clutch brake. I want to see 1/2 inch space between clutch brake and release bearing. I set up the clutch to get that measurement. Then you set you clutch pedal free travel. Usually I ball park it, about 1 inch free play on the pedal. That is adjusted by the pedal rods on the transmission.

To adjust the clutch, there are alot of youtube videos and you can google adj. Procedure. Its not hard. If you can do an oil change, tire change and general maintnance. You can adj. a clutch. Just easier to google the manual or video then for me to type it out.
 
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