I stumbled upon this thread and glad it's here. This is the most complete source I have found for info on these so far. I have some other information on the 6xxx and 7xxx I'll have to dig up and post.
Also, I have spoken to at least one truck shop that says they have these new. Many have rebuilds with prices ranging from $950 to $1500.
I am specifically looking to add a 5xxx, 6xxx, or 7xxx to my motorhome. I have a non-overdrive transmission and need to drop 500 or so RPM. In reviewing all my other options I think a Spicer auxiliary is the way to go. In the past few months I have come accross dozens of these, but since we are about to spend 3k on paint I have to wait a bit.+
Also wanteds to mention cable shifters - haven't seen anyone mention it here. COE tractors all have them, or you can buy one new, relocate a stock unit, or fab your own. Lots of people make control cables for applications like these.
My main concern is the torque capacity of these units. I have a Cummins 5.9 that will end up about 250hp and 500 ft-lb. I've read here (and other places) that they are rated for 500, 600, and 700 ft-lb respectively. Not exactly sure how this works, because my engine is already making 450.
I have read one other place that they are rated for 5000, 6000, and 7000 ft-lb total. Meaning peak engine torque x lowest gear ratio. This seems more realistic.
Anyways, I am looking for advice on which size unit to get. I have a motorhome with a GVW of 16k a GCVWR of 20k. A Cummins 5.9 that is 210 hp, 440 ft-lb now, and an Allison AT-542 tranny. 3.77 geared Dana HD-70, and 225-70-19.5 rubber.
I have 3 driveshaft hangers, so plenty of locations and room to mount this.
Any recommendations on which size to get?
Any thoughts on the market for making these types of boxes new? Or for manufacturing conversion kits for the input shafts of other transmissions? Essentially making a mounted unit an auxiliary?
spicer still make a unit similar to the old brownies but can't remember the series right nowthink it's like 740 and 840,I posted it a couple years back so a search may find it or go to spicers web site
there are several shifting options manual,cable or air
the torque ratings are 5000,6000 & 7000 ft lb
2000 F-350 2WD,DRW Auto, PSD,
DP Tuner,40 Tow 80E,Wicked Wheel 4" Exhaust ,AIS intake, Guages,6.0 Trans cooler to install, DooDad???=(dfuser ram air)
'98 Grand Cherokee, '86 F-150 SB Lariat 4x4 bought new (needs new home)
50pascals, I think an auxiliary that replaces an intermediate U-joint location in a multi-piece drive-shaft is an ideal solution for a motor home. It avoids replacing the tail-shaft of the main transmission and makes servicing more direct. The only downside I can think of at the moment is ground clearance.
Regarding torque ratings, I agree with your approach, but would add that the torque ratings are for continuous duty. The worst case I can think of is a truck in a pit mine that might grind without shifting gears for a serious amount of time dragging a full load up a steep incline. In a motor home this is not likely to be a problem. During the occasional time when you might have to "grind" along, you can probably do it in direct, and avoid any hard work for the auxiliary.
My Dad's Brownie was cable shifted and he never seemed to have any problem, including the two-part shift involved in double-clutching. There are (expensive) cables that use modern technology to reduce friction and elasticity, so I would recommend avoiding a cheap cable if you will shift a lot. If it is going behind an automatic, you might just leave it in direct or OD depending on the terrain involved.
I do not think we have focused on new units in this thread because of their cost. They are suitable for a working truck that is going to go millions of miles. For personal use, there are other options with the newer technology. I think I would go for a rebuilt with a warrantee as the best compromise between new and old. You would have to either pay a core charge or provide a core, but the price would be much less than new unit. Personally, I would just go for a "take off" -- a unit pulled out of a wrecked truck that was (more or less) in operational condition. (This would also be the best source for a core for a rebuild.)
__________________ Archie - w[size=1]orking on Fords since '63
Archie--WOW this is a great thread. I certainly appreciate your expertise along with ALL the contributors. I REALLY want to do the Brownie thing for my 95 SCab powerstroke 5 speed 4x2. I am getting raspberries from several friends following my previous diesel Suburban fiasco with an OLD Brown -Lipe oil slinging/ noisy rebuilt Aux. I could go with a USGear (Doug Nash 2)setting under the bench or the Spicer 5531(my preference). I need the lower gear for occasionally moving a trailer on hills etc...
I am greatly encouraged by this thread and your advise to others.
Just a gluttin for punishment I suppose-but I love the extra gears.
Concerning the Brownie in my old Suburban, after thinking on it a bit-it was a WATSON. This particular model did not use a front input shaft seal, only a slinger which at higher speeds would leak. I tried a shielded bearing and even a sealed(one side seal) bearing along with different lubes with no success. Just thought I had better set the "record " straight and cast no bad vibes toward B-L or spicer. Thanks once again for this great thread for real GREASERS.
Have enjoyed reading the Brownie threads. My towing rig is a 1986 F-250, 4 X 4, Super cab, 6.9.
Early ATS turbo with aluminum Ford Powerstroke intercooler.
Swapped out the T-19B (1.00, 1.41, 2.41, 4.01) close ratio box for a T-19A (1.00, 1.68, 3.09, 6.32), BW-1345 transfer case,
Spicer 7231-B (.86, 1.00, 1.24), 4.10 final drive with stock suspension and tires.
The 7231-A/B/C/D specifcations are maximum input 220-hp @ 450 ft-lb torque oil capacity 8-pints and 230-pounds.
The transmission was mounted divorced after the transfer case and not from the top as is normal but from the bottom across the frame
rail lower surface with 4 x 4 x 1/4 angle stiffening braces to the frame web (side).
U-channel was used with Part Master 60-2122 rubber body mounts used as isolation bushings.
The BW 1345 transfer case yoke is non-slip and secured with a nut in the stock application.
The yoke open end was closed with a welded in freeze plug.
Since the yoke secured the 1345 main shaft a spacer ring was inserted and a collar was installed behind the 1345 rear bearing.
Access to tighten the collar was made through the speedometer drive hole which was then closed with a freeze plug.
The 1345 now had a slip yoke. Yoke spacing has been set at .1-inch.
This gives a 1345 slip yoke spline engagement of 1.9-inch which is acceptable as the minimum slip yoke engagement rule of thumb is 1.5 x diameter.
The 1345 slip yoke connects to a 1350 flange yoke (NE 2-4853) that is mounted back to back with another 1350 flange yoke.
A 2 x 1/4-inch registration disk to centers them. The back to back 1350 flange yokes make up the 6-ich front driveshaft.
The front driveshaft connects to another 1350 flange yoke that is mounted on a 3/4-inch adapter disk.
The other side of the adapter is the 7231 four bolt small pattern (4-inch) companion flange.
The output side of the 7231 has the same companion flange and disk to a 1350 flange yoke. The rear driveshaft is 42-inches with slip joint at mid-extension.
The driveline angles are as follows: Front; 6.9/T-19/1345 9.3-degrees, front driveshaft 5.8-degrees, 7231 2.7-degrees, FWA 3.6-degrees,
RWA 3.1-degrees, with a difference of .5-degree.
This is acceptable for the driveline speed of <3150 RPM. Rear; 7231 2.7-degrees, driveshaft 7.7-degrees, pinion 2.7-degrees
(inserted 2.5-degree spring wedges to lower the pinion angle) FWA 5-degrees, RWA 5-degrees, Difference 0-degrees.
7231's are plentiful, 5000 series are hard to find parts for and will not take what a Powerstroke will output. 6000 might work but the 7000's are quieter.
Mine is reasonably quiet. Ended up cutting hole in rear floor. Used a 4-inch deep steam table stainless tray for the dog house cover.
Covered it with a section of matching carpet from junk yard and lined the inside with 3 layers of under hood fiberglass insulation.
The hole weakened the floor so make a 2 x 24 x 1/4 steel brace to fasten tranverse across front seat belt inner mounts.
The dog house is secured with 1 x 1 1/8 angle the braces the floor longitudinally.
Plenty of 7231's available and parts as well. 8000 series bigger and heavier.
7231 doesn't hang down too bad but I don't do off road. The hard to find part was the shifter.
It is mounted on the T-19 rear transmission mount on the passenger side. Shift lever and shift rods made from 5/8-inch rod.
Tried 1/2-inch but I could feel too much flex. Since anyone that has ever driven a 6.9 or 7.3 IDI will be aware that a drawback of the indirect injection is RPM wander.
A direct injection diesel is easier to control. What that means is clutch-less 7231 shifts are not dependable.
I use the half-clutch method. Depress the clutch just enough to neutralize the torque input to the 7231 so it will shift into neutral then a let out the
clutch and synchronize the shift with throttle. I tow the Sierra Nevada and I wanted to split 4th.
After I sat down and worked it out realized the 3L / 4O are almost identical to the Mack TRTL-722 Triplex that I drove years ago.
300 RPM splits are great. I can 2300-2600 up and down hills.
As far as going down hills I made an exhaust brake from a Cat 3208 exhaust recirculator. $35. It is air operated from a Lincoln air suspension air compressor.
When planning my descent I note the grade and speed and have the gears available to set my exhaust back pressure (other half of the dual air gauge)
and motor down the hill. I get a reasonable amount of braking in the 30-35 psi range. The 6.9 has a maximum exhaust back pressure of 45 psi.
Paid $900 for my 7231 from Acme in Stockton, California.
****** http-equiv="Content-Type" content="text/html; charset=utf-8">****** name="ProgId" content="Word.Document">****** name="Generator" content="Microsoft Word 11">****** name="Originator" content="Microsoft Word 11"> I just finished installing a Spicer 7231 auxiliary transmission in my motorhome. I wanted to share this with all of you, but some of the information will not necessarily be pertinent because I am writing this for posting on 3 different websites. Many people have talked about doing this, but I have never seen a write-up of someone that did. I did all this work with my own hands, with the exception of machining some spacers and final welding the cradle. My MIG welder is not big enough.
I have a 1992 motrohome with a stock 160 hp version Cummins 5.9, Allison AT542 transmission, 3.73:1 Dana HD70 and 225-70-19.5 tires. Chassis is an Oshkosh MC-16-FD, manufactured in 1991. It weighs 16k as we roll. I am not dinghy towing a car with this-yet. This is identical in every way to the 18k chassis with the exception of horsepower. The 18k chassis is 180 hp.
Our initial trips with this rig were fine, but slow. Top speed was roughly 62 mph on the governor at 2600rpm. On hills I would slow to roughly 50mph, no matter how big the hill. We got a solid 10mpg. Hills or flats, didn’t matter 10mpg wads the norm. The torque peak is basically flat, but the 50mph on hills was the clue as to where the “sweet spot” was in the torque curve.
After talking with my friend who owns a large diesel truck repair shop, I decided to make some changes. I investigated the logistics of changing transmissions, or using a modern day aftermarket auxiliary transmission. Changing the tranny was VERY expensive, and permanent. None of the currently available auxiliary OD transmissions would hold up behind this combination. So he suggested getting an old Spicer auxiliary gearbox.
He believes using the OD will get the Cummins in a better RPM range where we can actually go faster AND get more mpg. He believes I’m looking at 2 to 3mpg more. He also gave me a large a intercooler from an OTR truck which ought to get me 1 to 2 more.
For those that don’t know, this is a manual transmission, that is mounted after the main transmission. It is otherwise identical to a normal manual transmission except that it has a driveshaft in and out.
Pictures of the auxiliary project are here: Picasa Web Albums - 50pascals - Spicer Auxiliary
Whole motorhome project here: Picasa Web Albums - 50pascals - Motorhome
Spicer made variations of these units until the mid ‘70s. Mine is a 7231-D. “D” is the gearset for the box. Mine has a 2.14:1 under drive, 1:1 direct, and a .86:1 overdrive. I currently have no plans to use the under drive, which would yield a top speed of 37 mph. It can be shifted into low manually, but you would have to crawl under the rig to do it. The casting date on my case is 12-2-69. It was in a late ‘70s F-800 when I bought it.
This series of box was used in tandem axle dump trucks and some OTR trucks. It hauled much heavier loads, behind much bigger engines than I will. I am told it isnot possible for my rig to break this gearbox. One nice thing about this unit is that it has a neutral position. So if something goes wrong, you can shift to neutral and do not have to worry about your driveline parking brake.
This is a non-synchro unit. It must be shifted at very low speeds, or parked. I used an electric linear actuator from ebay and a custom linkage to shift the D-N-OD rail. Provisions are there, to use lawn tractor seat switches to turn on indicator lights on the dash to show what gear the box is currently in.
As far as mounting this thing. I did not want it to be the lowest point under the chassis. It turns out the stairs and the muffler are just a tad lower. I made a T shaped cradle that sits on top of the bottom web of the framerail in the rear, and has two legs going forward to catch the crossmember just behind the main tranny. I used rubber mounts from McMaster-Carr 6309k3 - $6 each. The majority of the weight is on the rear of the cradle, thus it sits on top of the bottom web. The front of the cradle bolts to brackets on the bottom of the crossmember. I used metal conduit reducer washers as shims to tweak the pitch of the gearbox for better driveline angles. They matched the OD and ID of the bushings perfectly. Plus the mounts are designed for 7/16” plate. I used 3/8”. I cut the existing ford rear mount and welded it to the cradle. I used the existing aluminum clamp mount up front.
This thing weighs close to 200 pounds. I can probably just barely bear hug it to move it from truck to stand. I stopped lifting it manually after I had the countershaft installed in the case. I parked the motorhome on 6” blocks. I wrapped the gearbox in a blanket and shrink-wrapped it. I used the engine hoist to set it onto a hand truck to get it to my wooden ramp. I used the ramp to shimmy the gearbox up onto my floor jack. I then jacked it into place and tightened and loctit’ed the bolts. The gearbox mounts rigidly to the cradle, the cradle uses rubber mounts to bolt to the frame.
It took 4 hours on a work stand to get the tranny perfectly level and aligned with the cradle. Then I tack welded everything and had the fab shop do the final welds. After it was all welded and painted I found out that the stock tranny pitches downward at a 6 degree angle. I then had to lower and pitch the gearbox. This was done by cutting the cradle down, and shimming the bushings, and also shimming the gearbox to the cradle. Luckily the rear flange had tweaked after final welding, which pitched the box perfectly. Five washers were used between the front mount and the cradle.
On our first trip, I left the box fixed in OD and noticed almost no difference in off-the-line acceleration. Highway driving was absolutely magnificent. Words cannot fully describe how happy we were with that box. Cruising on the governor was 70 to 72 mph. At one point on a slight downhill I hit almost 80, and immediately lifted! Uphills were about 53mph. It makes no noise inside – even when pressing your ear to the wood floor.
Top speed wasn’t our main goal, so I backed WAY out of the throttle and cruised between 65 and 67 for most of the trip. It takes quite a bit more pedal to rev the Cummins up to run on the governor. Interior noise was much lower – oddly lower. I kept thinking we were going slow.
As far as costs go. I bought the box for $300 off Ebay. I paid $150 to ship it. It needed to be rebuilt, that kit was $420. I then found out that the mechanics style yokes were trashed and no longer desirable for a highway vehicle. New companion flanges that would allow use of a 1410 or 1480 U-joint were going to be $300 apiece! I called a few friends and managed to scrounge up an acceptable companion flange for the input and a 1480 yoke for the output from a nearby junkyard. I also grabbed a few 1410 flange yokes and some other bits for a total of $37! The driveline shop was not as happy about this as I was!
I had the yokes sandblasted and needed to get custom spacers and machinery shims to get the thru-bore lengths right and get the new yokes in proper position for the seals. I needed to get two new seals for the input and output as well.
I painted everything myself, relocated the carrier bearing, and spent $420 for a new yoke shaft on the input side and to shorten my two rear shafts. I also added a heat shield for the exhaust. The yoke shaft on the input is 10 5/8” long. The rear shafts are roughly 48” and 41” long. The carrier bearing was moved back and mounted right to the crossmember and dropped ¾”.
One of the new yokes needed a new nut and a hardened washer. The various machining for spacers and the final welding (I just tacked everything) cost me $175. The steel to make the cradle (with plenty left over) cost $70.
Total cost was about $1600.
I can’t comment on fuel usage as we never filled it up, our first trip was too short. We will definitely do this on a later trip.
Before our next trip I will likely have the intercooler installed and have turned up the pump pressure a bit. I don’t care to take it right to 230hp, but a little more power to improve drivability while towing a car.
I did not hook up the speedometer to this gearbox. I used our GPS to figure the relevant speeds on our existing speedometer. I will someday.
Thanks for your contributions to this thread. The details & pics will inspire others to follow in your footsteps. I got a chance to buy a Roadranger RT-6600 for my F-350 -- now I have to get around to installing it in place of the current NP-540. It turns out that the 10-speed gives me the same ratios as I would get using a "Brownie" to split all the gears of the 5-speed.
__________________ Archie - w[size=1]orking on Fords since '63
I am new to the site, but have been following this thread for a while. It has helped a lot. I just put a 5831 B into my lifted 85 GMC. I made up the mounts, and am very happy with it. I am still making the shift rods to go from the shifter to the case. I was curious, does anyone know where I can get parts for this? My shift rail seals are leaking and one of the rails has a little pitting in the O/D position. This thing is noisy, I hope it is the cut of the gears (which I think it is) and not a bearing. One last question, it pops out of Direct, and I was wondering if this is a common problem or if I am looking at something bigger.
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