Dana Spicer 5831 3-speed auxiliary, .73 overdrive

[Stage1]

Hi,
Saw a Dana Spicer 5831 3-speed auxiliary, .73 overdrive unit hanging out the bottom of a very nice looking truck at JD's picture site. This looks very interesting. I did a search of the forum and did not find any previous posts on this subject. JD and others who have added an overdrive unit please provide a description of how you did this along w/ how it functions.

thanks,
Les

[gmctd]

The Dana Spicer 5830 series 3-speed auxiliary transmissions were manufactured in the '50s and '60s to provide gear-splitting and overdrive for ton-and-a-half and two-and-a-half ton trucks.
Similar in size and appearance to the the Muncie SM-465 4-speeds, some versions were two-under and direct drive, some were one-under, direct, and over drive, all synchro.
Many flange-mounted options were available, but now adaptor flanges\yokes will most likely require fabrication.

Spicer offered several larger series aux trans for up to, and including, 18-wheeler useage.

Remote shifting is via front mounted shifter assembly, thru two-rail system - passenger-side rail is 2:1 low and neutral, driver-side rail is direct, neutral, and overdrive in the 5831.

The 3500 series trucks with two-piece driveshaft have the center carrier member located in the upper frame rails, approximately above where this 5831 is now located.
Requires carrier crossmember removal
Requires modification to both driveshaft halves.

The front crossmember is the original center carrier mount, modified to accept the 5831 front collar support bolts and rubber isolators. Bolts are adjustable for proper driveline angles in radial and axial planes.
The rear crossmember is an '80s series GM transfer-case mount, split, dropped, and re-angled to correct frame-mounting plane .
Rear brackets are two-piece pivoting, to allow for driveline angle adjustment while maintaining correct setup of standard GM transfer-case bolts and isolators.

Shifting requires precision eye\ear and hand\foot coordination.
Up to speed in direct range, ease off accel, shift aux to neutral, drop eng\trans rpm to overdrive rpm, ease aux shifter into o\d range.
Synchros help, so a smooth hand can make it sound like an automatic up-shifting to higher gear.

Larger series have external pneumatic or electric shift setups, bolt-on.

Later - apologies for the numerical errors - numbers been berry berry bad to me! ;)

[ 03-04-2004, 04:57 PM: Message edited by: gmctd ]

[Stage1]

JD,

Thanks for the information- very interesting! One question, is it only for 2 wheel drive?

thanks,
Les

[gmctd]

Your choice, with isolated Dana t-case.

Not much use for overdrive while off-road in four wheel drive, IMO, so only the rear wheels need be over-driven.

Drops the 4.10's down to around 3:1

[84 Convert]

Nice! I do think the underdrive might be good for really slow crawling off road which woud be my only reason for even thinking about the more difficult pre-t-case install. What should one expect to pay for a unit like this? I'm always looking for less expensive ways to do things.

Gregg

[gmctd]

Problem will be in finding one.

Typical response, while I was looking for info\parts, was a snickered
'Whut chew want it fer? Ain't seen one uv 'em in years!'
'Yew ever seen one, Joe-Bob?'
'Whut - naw!'
Ptui! (Chaw misses coffee-can target)
'Djew try Terminated Auto Parts? Mebbe they got some.'

I'd say just buy it, if you find one.

[ 03-04-2004, 05:03 PM: Message edited by: gmctd ]

[britannic]

These guys may be able to help: Boyce Military Equipment (http://www.boyceequipment.com/)

[84 Convert]

Sounds like my kinda parts! That's about the kind of response I got when replacing the input bearing on my OD 4sp. manual. Very interesting, though.

Gregg

[crew84]

I found a link that you guys might find interesting.

GM tranny and Spicer Info (http://www.6066gmctrucks.org/spicer-5831-b.htm)

[gmctd]

You done good, crew!!

Thanks.

The info he is missing is for the 5831, no alpha, which is the version I have.
The mfg date is 11\57!

"Brownie" was the accepted colloquialism for the 5831 series.

The formal colloquialism, however, is "Brown-lite" :rolleyes:

[ 03-04-2004, 05:19 PM: Message edited by: gmctd ]