question Re: ownwers / drivers of Spicer 4sp buses (past & present)

[FloridaCliff]

Mark,

I had never driven a double clutched vehicle or a Bus before I bought my 4905.

I have driven lots of heavy vehicles that had manual trannys.

That said, there was a learning curve involved in this "shifting thing".

My drive home was more of a "grind than find em" ride.

I guess the hardest thing to get used to was that I basically had to wind it out to the governor, then shift.

Just didn't seem natural to my other shifting experiences and plus I have a five speed Jeep that I dive daily and the shifting is just the

opposite.

After reading R. J. Longs article on shifting and making my brain think different, I was amazed at how well the bus started shifting.

My suggestion to anyone wanting to learn would be to 1st read R.J.'s article and then pick a road were you can go through a lot of

starts and stops.  This is usually best done by yourself if you know what I mean

I am at 90% competency on the shifting, make a clean shift most of the time, miss one now and then....Must be the linkage is out

of adjustment   Yeah, thats what it is!

Cliff

[DMoedave]

The double clutching is easy and a way of life once ya got it and in our bus we dident need to use the clutch after starting in first . Wind er out let of the pedal while pulling it out of 1st and let the revs drop ( i counted 1-2-3 shift) and wind er out again and repeat. works well unless going up or down a hill which varied the lag time for the shift. First thru third was fine  but the long pull in 4th to top speed was the killer to me. Most GM's with the 4 speed suffer that. Our reverse was also to highly geared.

[Homegrowndiesel]

Ok Cool

We bought our Eagle with the 4 speed in it. pulled the engine & trans during refurb, and reused when we put bus back together.

First time Spicer driver, but have driven plenty of manual trans in the past. As has been noted, you only use the clutch to get started or stopped, time your shifts, and throttle.

I always thought I HAD to have an auto also, until I drove it with the stick, No problems (except as noted by others, but manual drivers have had to overcome for years) that patience and practice can't overcome. (maybe $$ and clutches if you are a slow learner, or  trying to learn on some of the noted bad grades.)

The Eagle has an air assist clutch pedal that is a dream to work. I like the looks of the GM's but have not driven one.

Goon luck with your choices, find fellow busnuts as previous posts had suggested and check it out.

Oh yea get more bus to start with, you will be happier, and cheaper off in long run. Unless you are NUTS like the rest of us, and just like the looks of a certain coach, or are a tinkerer.

Bill

[jason357]

GM 4104 Spicer GRINDS GEARS BAD i drove it home now it wont move

If the four speed isn't to your liking replace it with a 5 or 6 spicer or maybe a 8 or 10 speed roadranger trans.

I think his original question concerned GMCs, so this is just an FYI about GMCs.

Unfortunately, GMC's v-drive engines have a very limited number of transmissions (stick or slush) that will work with them. The 671 without serious modification will only take a 4-speed. An 8v71 can take a 4-speed Spicer, or an Allison VS2-8 or V-730 (or a couple of one or two-speed transit Allisons I won't mention). That's it. Anything else requires major ($$$) mods.

T-drives are a whole 'nuther story. But the only common GMC with a t-drive is the Scenic.

Personally, I'd prefer a RR 10-speed over most slushboxes, since it eliminates most of the issues I had with a stick-shift coach... but these are only available for t-drives.

HTH,
Brian

[TedsBUSted]

Hello Jason357,

You'll have to be more specific before anyone can give you a decent reply.

"Grinds gears bad" - Did you hear grinding noise when moving, after completed shifts?

Won't move?
When depressing the pedal the clutch won't release, so the trans can't be pulled into gear?
-or-
Trans can be pulled into gear but engaging the clutch (releasing the pedal) has no effect?

Does the drive-shaft turn while the bus is not moving, indicating a differential or axle failure?

---

[bwze]

I'm new to this whole bus world too. My search for a bus involved driving autos and 4 speeds. Loved the autos, but couldn't find one in my price range in the condition I wanted. Ended up located this 4106 we currently have and it came with the Spicer. I've had it for just over two months now. For most of those two months it sat up on blocks while I serviced the brakes and various other components. In the last two weeks, however, I've been able to get it out and run through its paces. I feel extremely comfortable with the upshifts. And that statement by Tom about the oil temp affecting shift timing is so true....took me a while to figure it out. My only problem is with the downshifting.... ... I live in a neighborhood with an empty street about a 1/4 mile long that gives me a good practing field, so to speak. It's long enough for me to get up to third gear and then attempt a 3rd to 2nd downshift. Sometimes I get it but most times I don't. I'm just not sure of what I should be doing. Brian mentioned visualization of the input and output shafts to help aid in shifting....Brian, would you care to expand on this or can anyone give me a good explanation of the process of downshifting so I wrap my head around it? I've read RJ's article and understand the uphill shifting pattern, but how about on level ground.....

[thejumpsuitman]

When I stared looking for a bus I had the same question.  I was finally able to drive a 4104 with the 4 spd. Spicer and actually enjoyed the experience.  However, if you ever get stuck in crawling traffic, it might be a pain.  Even though we wound up buying a bus with a automatic, I would not have been scared off if the right bus that came along had a stick.  There are benefits, including simplicity, MUCH cheaper repairs and better fuel mileage.  They were built with those trannys, so if they could drive them back then and others can now, so can you if you believe you can.

[bevans6]

I have an MCI with a Spicer 4 speed.  I think the clutch and shift linkage setup on the MCI is more driver friendly than the GM, from what I've heard.  My clutch is too heavy for comfort, but in taking the engine out I was able to see that the linkage was adjusted wrong, and I also have  a plan to hot-rod the air assist if the adjustments don't get it light enough.

In my opinion, having inspected the shift hubs and dog engagements inside a Spicer 8844, it is not designed to be shifted without a clutch, but it obviously can be.  The dog splines are too small and fine for easy clutch-less shifting.  shifting with the clutch but without double clutching is better for it, and double clutching just helps things out that much more by making it easier to match the gear speeds inside the box.  Since I own my gearbox and have to pay for it if I break it, I double clutch up and down.

Downshifting is the hardest part to learn, and there is a trick - speed!  With both up and down shifting, how fast you time the shift is the important part.  Downshifting from 4th to 3rd is the most common, the trick is to start the shift at the road speed that you would be on the governor in third, or if you are on an uphill  grade, a few mph faster than top of third, clutch out, neutral, floor the throttle pedal for maximum revs, clutch, slip into gear.  And do it as fast as your feet and hands will move.  third to second, same deal but a little slower.  second to first, quite slow.  I find I really need to put a lot of throttle in it to get the engine up to speed to accept the lower gear.

I took around 2000 miles to learn how to upshift to where I mostly get the next gear with little more than a handshake or a silent engagement, and around 5000 miles to get smooth, repeatable downshifts.  That was over around 8 months of driving sporadically.  If you drove every day like a bus driver would, you'd take about a week to learn what I took close to a year and several long trips.

Brian

[Barn Owl]

Wow! This is resurrecting a thread from the past. Eventually you can learn to shift w/o the clutch but it takes lots of miles and practice. I learned on one of my old employer's Dump Truck how to shift so smooth that it became fun to show off my skill. The problem is that every machine is a little different and it takes more time and practice to transfer that ability to other trannys. If you are not driving it everyday, all day, then I would most defiantly double clutch both up and down. Easiest on the transmission, but not so easy on your left knee. If your linkage is way out that might explain the difficultly in shifting and no being able to move it now. I think you need to have someone that is very familiar with how they are supposed to work offer you a hand and take a look at it.

[lostagain]

Have driven lots of MCIs (5s, 7s)with the 4 speed in the '70s and '80s. It gets to be second nature. We would drive them in and out of tight spots, up and down steep hills, etc. The company had to rebuild clutches though, LOL. In driver training, they taught us to double clutch, always. No clutchless shifting. (This is a subject that has been debated here at length and could be again ad vitam eternam, so I'll stay out of it this time.)

My new bus since last spring has an Allison 740 and I love it. Great for tight spots, around town, and starting up steep hills. And there is just as much control and feel as with a manual.

JC

[Runcutter]

Jason, I'll second the request for more information, on what it is, and is not doing.  Let's add a request, post your location (see the bottom of this post) - for all members, new and "old", a location can get you personal help.  One of us may be nearby.  

If you're grinding when trying to go into first from a dead stop, unfortunately that seems to be somewhat normal.  My 4107 does that, I often end up shutting the engine down, go into first, and restart.  It was normal when the coaches were in service.  I both drove, and instructed on 4903's and 4905's.  

I would start folks out on schoolbuses, so they could learn to shift, then transits, so they could learn to maneuver.  When they were promoted to coaches, they'd have to learn both.  The non-synchromesh transmission does require double-clutching.  Occasionally, I would shift without the clutch, so I knew I could get a bus home in an emergency.  I wouldn't do that with my 4107, though, since it already knows the numbers of my credit cards.  Also, each coach was different.  I had a favorite 4905, seems like I never missed a shift, up or down.  Her sister, bought the same year, was good, but not quite as good.  Two years later, the company bought another two 4905's, the first year of air throttle.  I couldn't shift the darned (not the word I want, but it'll do) things -- so I sure wouldn't use them for instructing.  It also seems like each coach likes a different speed of action, and even that may vary with temperature.  We had a little 35 foot suburban (SDM4501) that had a 4104 transmission in it -- fastest shifting little bus I ever drove.  Others were more leisurely.  You have to learn your specific bus.  

It's a pat your head, rub your stomach thing, particularly downshifting.  Fourth to third - left hand on the wheel (don't forget, you're steering).  Right hand on the stick.  Left foot - clutch in, right hand fourth to neutral, clutch out.  Right foot, goose the throttle, to match shaft speeds.  Left foot, clutch in, right hand neutral to third, clutch out, while your right foot is working to match speed so the passenger don't know you shifted.  Smooth is the word.  

Although I bought the 4107 in part because it had the original 4-speed, and I used to find great satisfaction in smooth shifting, we're now putting a V-730 in.  Reason, we've come to the conclusion that my wife will not be able to learn to drive a stick.  I don't have a fleet, so I can not first teach her simple stick (with synchronizers), bus maneuvering, and then go to the non-synchro 4-speed, in a progression.

Please give us more information, we may be able to help.

Arthur        

[Lin]

Shifting and double clutching are not the issues with the Spicer 4 speed.  The real problem is the ratios at first gear and reverse.  Think of it as a 5 speed transmission where 1st gear does not work.  You could learn to live that way, but why would you want to.  Reverse is just as bad but less critical.

[RJ]

Jason and BWZE -

Call me, my number's in my profile to the left.  Remember I'm in CA, so adjust the time zone accordingly.

I'll see if I can help talk you thru the situation.

FWIW & HTH. . .

[bwze]

RJ, thanks so much for the offer, but I GOT IT....went out this afternoon and practiced my downshifting and then practiced some more. I finally got it. I even got a name for it......the Double Clutch Two Step. Of course, this was on somewhat level ground, but I'll tackle the hills later.....