Why Does Everyone Hate Spicer Trans?

[wlhequipment]

I don't follow the market for old used transmissions, but that does not seem spendy at all for what it is.

Actually, yea I’ll agree with ya there.

 

[Jumbo]

OK, makes sense to me.

 

[Spud_Monkey]

I think those hydraulic like locks, even the nice ones that Coaldust pointed out, I believe have legality issues. I'm not required to get a DOT number yet, but if I do, and get inspected, they will fail me for those, if there is no other parking brake available. They can't be the main parking brake, from a legal standpoint, is all I'm saying. SpudMonkey, I read your whole thread on your trans. We're in the same boat, and that 6206 is a bit cheaper than a RT6610.

I passed my "first" CDL test with line lock brake so it must be some legality to it. Just as I passed my "second" CDL test Class A (Tanker, Double/Triple endorsement) with a rig with air brakes and no air brake restrictions even though I had a gooseneck trailer with electric brakes. Just need to read between the lines.

 

[Willie B]

What exactly is your issue with the existing transmission? What do you think a 5 speed will fix about it?

Has anybody here heard of anybody installing a Roadranger in a non air [work] truck? All it would need would be a *reliable8 small electric air compressor.

My gut feeling is the splits on the 5 speed would be so wide, you will wish you had the automatic back.

Another option would be a lockup automatic, MT 6xx series. There have to be donor trucks all over in this configuration.

I'd have said my MT643? in the 28000 LB gross fire truck was handicapped by not having torque converter action in top two gears. Lock up is fine once I reach synchronous speed, but the clunk as it shifts to 3rd or 4th seems to waste power. All in all, it behaves acceptably, climbs steep hills slowly, Differential is approx. 5 to 1, so 2500 RPM is 65 MPH. The 3208 wants to run best at 1800 to 2000 RPM. I would love a 10 speed, I imagine that'd be a big job to convert.

 

[colson04]

Wow, lots of responses, but I never got the email notice. Geez, sorry guys I'll try to keep up.

I looked into the MT643, and I didn't find any option with the parking brake drum. I'll look some more. That would be the easiest option. Well, the easiest option would be, as Birken pointed out, leave it alone and not to tow in the mountains with this pig. I'd like to fix it though. I like everything else about this truck. It's simple, no computer, no EPA, also no ballz, but I'm hoping to fix that. I think those hydraulic like locks, even the nice ones that Coaldust pointed out, I believe have legality issues. I'm not required to get a DOT number yet, but if I do, and get inspected, they will fail me for those, if there is no other parking brake available. They can't be the main parking brake, from a legal standpoint, is all I'm saying. SpudMonkey, I read your whole thread on your trans. We're in the same boat, and that 6206 is a bit cheaper than a RT6610. I have my HX40 turbo ready to install, I'm just waiting on the time to do it. Also going to turn up the pump, and advance it a bit. I have EGT and Trans Temp gauges installed already. Max trans temp is 275, and when I was towing that tractor in the steep hills outside Evergreen, CO, I was slowly creeping up. It got up to 250, and I would stop for awhile, let it cool down, and go again. Slowly. It would start to smell like something's burning HAH. This truck is just too big for an automatic, in my opinion. I'm an old - school hands - on kinda guy anyway. I like to be in more control of heavy things . I don't mind going slow and chugging up hills with my 4 ways on, I just don't want to be burning up stuff while doing it.

Well, I'll be damned...

https://www.heavytruckparts.net/item/Allison/Mt643/Transmission-Assembly/65930/1/19153

They do have brakes. Also, oddly, this place is maybe an hour from me. They're the guys I got my frame rails from when I stretched 'er. A little spendy for an old trans, but this might be just a drop in fix. I'mma give this one some thought.

It's been 3 years, but I bought a reman MT653 for my International dump truck with DT466 for $2500. I did not have or need a driveline brake as I did have air. I see used 643/653s come for sale from $500 to $1000 on a regular basis.

On the hydraulic line lock - there must be some legal basis for them as we owned a late 80's F-750 that did not have air, that had a parking brake knob you pulled out on dash. When pulled, you heard an electric buzzing, and then the brake pedal got firm. You could then shut her down and walk away. When I was shopping for a single axle dump truck, I ran across several of these trucks while i was shopping

 

[wlhequipment]

In that pic I posted of the truck and tractor, I think I was close to 25K GCW. I know for sure the truck is 15K. The trailer is 4K, and I think the tractor was around 6K. The 545 is rated at 30K max. I was towing in the mountains, etc so I was probably pushing that little slush box to its limit. I guess I should be happy I even made it home . An MT653 is rated at 70K, and would require me shortening the driveshaft about 10”. When I stretched the frame, which was a total PITA I will never do again (yes it’s all on my YouTube channel), I took the DS to a local shop to extend it the required 18”. The DS was a one piece, but the additional length mandated a carrier bearing and a 2-piece. So I put in an additional frame crossmember, and did all the driveline calcs, had to shim the rear axle to make the angles work etc etc. Total drag, but got it done and it’s been just fine. But now, since that 653 is 10” longer, I think I’m going to have to move my crossmember, which will effect my driveline angles. I think that crossmember is 16” behind the 545. If the 653 takes up 10 of those, that would mean I’d have a crossmember and carrier bearing 6” behind the trans. This is what happens when you start customizing trucks I guess

 

[colson04]

I had a 653 in a single axle truck, grossing 33,000 to 35,000 leaving the pit. Probably more when I did site work.

My grandpa has 3 Ford trucks with MT653 in them, all tandem drive grossing 50-55,000 when we cross scales. Our only issues have been related to prior owners lack of maintenance, or our own abuse in soft ground. The one truck pulls a tag with our 590D Deer excavator on it. Not setting any records, but it gets the job done.

 

[Old Doug]

It's been 3 years, but I bought a reman MT653 for my International dump truck with DT466 for $2500. I did not have or need a driveline brake as I did have air. I see used 643/653s come for sale from $500 to $1000 on a regular basis.

On the hydraulic line lock - there must be some legal basis for them as we owned a late 80's F-750 that did not have air, that had a parking brake knob you pulled out on dash. When pulled, you heard an electric buzzing, and then the brake pedal got firm. You could then shut her down and walk away. When I was shopping for a single axle dump truck, I ran across several of these trucks while i was shopping

Thats not a line lock run away as fast as you can. Dont as any?? just run.

 

[Old Doug]

I would not trust a line lock as a park brake. I dont like the thought of what could go wrong if thats what i had i would also use wheel chocks.

 

[wlhequipment]

I would not trust a line lock as a park brake. I dont like the thought of what could go wrong if thats what i had i would also use wheel chocks.

I use one on my forklift because the OEM brake is not made anymore. I only run the fork a few times a week, but I need a brake that works. Granted, I installed one of those cheapo line locks, but it fails all the time. I have a few sitting on the shelf I just change em out. They’re fine for the fork, but yes agreed, I would not put one in the truck.

 

[Birken Vogt]

I thought it was the general opinion on here that line locks cause wheel cylinders to fail due to the constant (high) pressure. As well as the danger of it leaking away over a long time. Good for tow trucks that need to winch with all 4 wheels locked but only for the duration required.

 

[colson04]

Thats not a line lock run away as fast as you can. Dont as any?? just run.

Lucas girling hydarulic brakes. I had to look it up, but I see they are damn expensive to work on. We sold the F-750 we had about 5 years ago. The brakes never gave us any fits, always worked, but we needed more capacity that that truck could haul so away she went.
All of the single axle dumps I saw it on were gas engine rigs that I didn't want to mess with.

 

[59 North]

I'd have said my MT643? in the 28000 LB gross fire truck was handicapped by not having torque converter action in top two gears. Lock up is fine once I reach synchronous speed, but the clunk as it shifts to 3rd or 4th seems to waste power. All in all, it behaves acceptably, climbs steep hills slowly, Differential is approx. 5 to 1, so 2500 RPM is 65 MPH. The 3208 wants to run best at 1800 to 2000 RPM. I would love a 10 speed, I imagine that'd be a big job to convert.

In the late '80s where I worked, if I recall correctly, we had a mechanic truck with the 3208 and 10 spd, and the combination seemed to work ok on the highway. Truck was a, GMC with air brakes, service body with an IMT crane etc, so was heavy. Truck was fairly new then. Had the pickup style cab and tilt hood.

 

[Truck Shop]

Unless laws have changed a Mico brake lock is not legal for parking.

 

[Willie B]

In the late '80s where I worked, if I recall correctly, we had a mechanic truck with the 3208 and 10 spd, and the combination seemed to work ok on the highway. Truck was a, GMC with air brakes, service body with an IMT crane etc, so was heavy. Truck was fairly new then. Had the pickup style cab and tilt hood.

Yup.
Mine is GMC Top Kick. 1990. Other engines, GMC switched to the then current pickup cab. The 3208 & a few other engines they stayed with the 1973-1987 square body pickup cab. There is a lot of extra stuff surrounding it, you have to look close to recognize the pickup cab.
It's quite sporty empty, reasonably adequate loaded, but hitch a trailer carrying an 18000 LB backhoe behind it, it gets slow.

 

[materthegreater]

In that pic I posted of the truck and tractor, I think I was close to 25K GCW. I know for sure the truck is 15K. The trailer is 4K, and I think the tractor was around 6K. The 545 is rated at 30K max. I was towing in the mountains, etc so I was probably pushing that little slush box to its limit. I guess I should be happy I even made it home . An MT653 is rated at 70K, and would require me shortening the driveshaft about 10”. When I stretched the frame, which was a total PITA I will never do again (yes it’s all on my YouTube channel), I took the DS to a local shop to extend it the required 18”. The DS was a one piece, but the additional length mandated a carrier bearing and a 2-piece. So I put in an additional frame crossmember, and did all the driveline calcs, had to shim the rear axle to make the angles work etc etc. Total drag, but got it done and it’s been just fine. But now, since that 653 is 10” longer, I think I’m going to have to move my crossmember, which will effect my driveline angles. I think that crossmember is 16” behind the 545. If the 653 takes up 10 of those, that would mean I’d have a crossmember and carrier bearing 6” behind the trans. This is what happens when you start customizing trucks I guess

Just curious where you find weight ratings for different transmissions. I don't know much about trucks but am curious to learn how to calculate towing capacity, and obviously the transmission plays a big part in that.

 

[Willie B]

A few years back I researched specifications for the MT643. I didn't find much except torque & horsepower ratings. They seemed to choose transmission based on truck weight & engine. Though, I've never seen a tow rating or Gross Combined.

This is a subject I hear often. I see smaller single axle trucks outfitted as a semi. Their drivetrain, I know nothing of.

One self described expert says in CDL sized trucks it's about rear axle weight. To me, that doesn't seem logical. Mine, I figure I'm towing 23000, I wouldn't want more than that.

 

[Truck Shop]

Class trucks the trans and axles are matched to engine torque and horse power. The brake
shoe lining is rated at 23K lbs for premium lining. The towing hauling weight is calculated
by how many axles and bridge laws going by gvw.

 

[wlhequipment]

Just curious where you find weight ratings for different transmissions. I don't know much about trucks but am curious to learn how to calculate towing capacity, and obviously the transmission plays a big part in that.

Just look up the data sheet for the trans. Like this one for the 653
https://www.dal-trans.com.au/files/MT-653_-MTB-653.pdf

look at a couple of them. If you find 2 or 3 that say the same thing, you’re fairly well assured it’s accurate.

 

[59 North]

Yup. View attachment 249731
Mine is GMC Top Kick. 1990. Other engines, GMC switched to the then current pickup cab. The 3208 & a few other engines they stayed with the 1973-1987 square body pickup cab. There is a lot of extra stuff surrounding it, you have to look close to recognize the pickup cab.
It's quite sporty empty, reasonably adequate loaded, but hitch a trailer carrying an 18000 LB backhoe behind it, it gets slow.

Even about the same color. The tilt hood was a real plus , as it was crowded.
There was also a similar truck on the site that was a 4x4 conversion, had the 8.2 Detroit 4 cycle diesel and Allison. Don't recall that setup being much of a road truck!