Gear Ratio & Tire Size Options For A D600?? - Moparts Forums

Register Log In Moparts Forums Sandy's Truck Shop Gear Ratio & Tire Size Options For A D600??

Print Thread

Page 1 of 2

1

2

Gear Ratio & Tire Size Options For A D600?? #1641770 07/03/14 08:35 PM 07/03/14 08:35 PM
Joined: Mar 2007 Posts: 2,525 Louisville, KY E E-Ticket OP master
E-Ticket OP master E Joined: Mar 2007 Posts: 2,525 Louisville, KY	ok.......so I have this 1974 D600 with a 361, 4-speed + 2 speed rear axle that I bought originally to do some scrap & crap hauling and have also considered converting it to a car hauler because its absolutely perfect for such a project due to the need for "stretching" the frame is not required on this one....just add some length to the end of the rails and your golden...... I do have it currently for sale here on Moparts but if it does not sell soon, rather than let it sit, I am still considering the ramp bed conversion? Two things that I would have to consider changing if the options are available is to maybe change the rear end gear ratio to a higher gear and would like to put a smaller diameter wheel & tire on it OR instead of changing the rear center section out for higher gears....maybe change it over to a 5-speed or 6-speed transmission?? My questions are.....does anyone know what if any higher gear ratio gear options are available and also....how much smaller of this type of wheel & tire can I put on it in order to lower the truck closer to the ground? It currently has 9.00 x 20 tires and I believe the rear ratio is a 5:57/7:60 in an Eaton Planetary Spiral Bevel type rear end. 8196596-I.jpg (454 downloads) "Fat drunk and stupid is no way to go through life son......" http://www.youtube.com/watch?v=bK-Dqj4fHmM

Re: Gear Ratio & Tire Size Options For A D600?? [Re: E-Ticket] #1641771 07/04/14 12:45 PM 07/04/14 12:45 PM
Joined: Feb 2013 Posts: 760 Canada C CTD5.9 super stock
CTD5.9 super stock C Joined: Feb 2013 Posts: 760 Canada	I am currently trying to do the something similar with one. In my case I am putting a club cab and a flat deck on and using it to tow a big goose neck. Mine is getting a 5.9 cummins so I need to get the rpms down, I have not for the life of me been able to find different gear sets for that diff. I have began the search for an auxilary transmission though, either a spicer or brown-lipe with an over drive in it. As for tires the 20's are fairly out dated, I think 22.5's are fairly common. There are some lower profile ones out there but I am not sure how the rims would work on the trucks dayton system.

Re: Gear Ratio & Tire Size Options For A D600?? [Re: CTD5.9] #1641772 07/07/14 05:09 PM 07/07/14 05:09 PM
Joined: Dec 2005 Posts: 586 UP F finn mopar
finn mopar F Joined: Dec 2005 Posts: 586 UP	19.5 rims are popular with "LoPro" medium trucks, but I see the truck you pictured has the old Dayton style hubs and rims. You would have to switch your axles out to hub piloted Budds from a later truck. That would get you better (Disc) brakes, although all of the recent trucks have antilock systems which is a further complication. Unless you can pick up a decommissioned school bus donor cheap, you may want to just enjoy the old girl for what she is: a 50 mph local hauler.

Re: Gear Ratio & Tire Size Options For A D600?? [Re: CTD5.9] #1641773 07/08/14 06:14 PM 07/08/14 06:14 PM
Joined: Mar 2007 Posts: 2,525 Louisville, KY E E-Ticket OP master
E-Ticket OP master E Joined: Mar 2007 Posts: 2,525 Louisville, KY	Quote: I am currently trying to do the something similar with one. In my case I am putting a club cab and a flat deck on and using it to tow a big goose neck. Mine is getting a 5.9 cummins so I need to get the rpms down, I have not for the life of me been able to find different gear sets for that diff. I have began the search for an auxilary transmission though, either a spicer or brown-lipe with an over drive in it. As for tires the 20's are fairly out dated, I think 22.5's are fairly common. There are some lower profile ones out there but I am not sure how the rims would work on the trucks dayton system. That is what I am running into also as far as not finding info. on optional gear sets......thanks!!! "Fat drunk and stupid is no way to go through life son......" http://www.youtube.com/watch?v=bK-Dqj4fHmM

Re: Gear Ratio & Tire Size Options For A D600?? [Re: finn] #1641774 07/08/14 06:20 PM 07/08/14 06:20 PM
Joined: Mar 2007 Posts: 2,525 Louisville, KY E E-Ticket OP master
E-Ticket OP master E Joined: Mar 2007 Posts: 2,525 Louisville, KY	Quote: 19.5 rims are popular with "LoPro" medium trucks, but I see the truck you pictured has the old Dayton style hubs and rims. You would have to switch your axles out to hub piloted Budds from a later truck. That would get you better (Disc) brakes, although all of the recent trucks have antilock systems which is a further complication. Unless you can pick up a decommissioned school bus donor cheap, you may want to just enjoy the old girl for what she is: a 50 mph local hauler. yeah....reality is setting in on a few things unless I want to just change out everything like the drivetrain over to a 12 valve with a 6-speed and change the rear end also..... Not sure I am that excited about changing this much for the purpose?? I have got this "big girl" up over 60 mph fairly easy so its not so horrible the way she is now..... "Fat drunk and stupid is no way to go through life son......" http://www.youtube.com/watch?v=bK-Dqj4fHmM

Re: Gear Ratio & Tire Size Options For A D600?? [Re: E-Ticket] #1641775 07/08/14 06:59 PM 07/08/14 06:59 PM
Joined: Feb 2006 Posts: 2,262 Groveland, MA SteveS top fuel
SteveS top fuel Joined: Feb 2006 Posts: 2,262 Groveland, MA	I had an F600 of about the same vintage (1978). It had a wide ratio 5-speed, with a single speed rear. It had 22.5" tubeless steel wheels, with somewhat lower profile tires. It would cruise pretty well at 70. Steve Someday I'll have another C-body.

Re: Gear Ratio & Tire Size Options For A D600?? [Re: SteveS] #1641776 07/15/14 02:15 PM 07/15/14 02:15 PM
Joined: Jan 2003 Posts: 16,376 D dogdays I Live Here
dogdays I Live Here D Joined: Jan 2003 Posts: 16,376	First of all do you understand that making the tires smaller diameter increases the rpm at 60? So going smaller on the tires and to a higher speed rear would work against each other. I'd start looking for an auxiliary transmission to go behind whatever transmission you end up with. Or use something like a late model car 6-speed with 0.50 Sixth gear. R.

Re: Gear Ratio & Tire Size Options For A D600?? [Re: dogdays] #1641777 07/16/14 11:58 PM 07/16/14 11:58 PM
Joined: Dec 2005 Posts: 586 UP F finn mopar
finn mopar F Joined: Dec 2005 Posts: 586 UP	A car transmission means you loose the transmission mounted parking brake of the medium truck. Also, the first gear ratio would be too high to get the thing rolling when loaded. The truck probably has a SAE type bellhousing & mounting system too.

Re: Gear Ratio & Tire Size Options For A D600?? [Re: finn] #1641778 07/17/14 07:12 PM 07/17/14 07:12 PM
Joined: Jan 2003 Posts: 16,376 D dogdays I Live Here
dogdays I Live Here D Joined: Jan 2003 Posts: 16,376	http://www.olddodges.com/dseries.htm has as good of information as I found online. The D600 used an NP435 transmission as the standard, although a couple of five-speeds were available. Engines were 318 and 361, and clutches were 12" with 13" optional. The gasoline engines did not use SAE bellhousings. R.

Re: Gear Ratio & Tire Size Options For A D600?? [Re: dogdays] #1641779 07/19/14 02:32 PM 07/19/14 02:32 PM
Joined: Mar 2007 Posts: 2,525 Louisville, KY E E-Ticket OP master
E-Ticket OP master E Joined: Mar 2007 Posts: 2,525 Louisville, KY	Quote: http://www.olddodges.com/dseries.htm has as good of information as I found online. The D600 used an NP435 transmission as the standard, although a couple of five-speeds were available. Engines were 318 and 361, and clutches were 12" with 13" optional. The gasoline engines did not use SAE bellhousings. R. thanks.....I saw that link also and it is a strong wealth of information! If I do ever get the chance to make a change, it will most likely be for a 5 speed with this motor or a 6-speed with a 12 valve CTD?? "Fat drunk and stupid is no way to go through life son......" http://www.youtube.com/watch?v=bK-Dqj4fHmM

Re: Gear Ratio & Tire Size Options For A D600?? [Re: E-Ticket] #1641780 07/19/14 04:26 PM 07/19/14 04:26 PM
Joined: Dec 2009 Posts: 284 STL ,MO H Handygun enthusiast
Handygun enthusiast H Joined: Dec 2009 Posts: 284 STL ,MO	The 22.5 Dayton hoops will fit your drums, the np-540 is direct in top just like the 435. A Dodge CTD is a neat idea but what a can of worms that opens up ie parking drum and transmissions with overdrive. There are 2 D-600's heavy and light. the last one I had weighed 9900 empty. it was a 197wb, Daytons, 24k gvw,same drive train as yours 16ft flatbed. Put 5 tons of scrap on there and that asking a lot out of a Getrag.

Re: Gear Ratio & Tire Size Options For A D600?? [Re: Handygun] #1641781 08/08/14 03:46 AM 08/08/14 03:46 AM
Joined: Mar 2007 Posts: 2,525 Louisville, KY E E-Ticket OP master
E-Ticket OP master E Joined: Mar 2007 Posts: 2,525 Louisville, KY	ok.....anyone ever taken a truck this size and changed the chassis down to a D300, 1 Ton Chassis?? "Fat drunk and stupid is no way to go through life son......" http://www.youtube.com/watch?v=bK-Dqj4fHmM

Re: Gear Ratio & Tire Size Options For A D600?? [Re: E-Ticket] #1641782 08/08/14 12:09 PM 08/08/14 12:09 PM
Joined: Feb 2013 Posts: 760 Canada C CTD5.9 super stock
CTD5.9 super stock C Joined: Feb 2013 Posts: 760 Canada	The cabs are the same, with just taller mounts to raise it up. I am not sure about the rest of it mounting onto a 1 ton frame

Re: Gear Ratio & Tire Size Options For A D600?? [Re: CTD5.9] #1641783 08/08/14 12:19 PM 08/08/14 12:19 PM
Joined: Mar 2007 Posts: 2,525 Louisville, KY E E-Ticket OP master
E-Ticket OP master E Joined: Mar 2007 Posts: 2,525 Louisville, KY	If I had at least a D100 or D200 to sit next to it, I could at least compare them side by side and do some measuring but I don't........ "Fat drunk and stupid is no way to go through life son......" http://www.youtube.com/watch?v=bK-Dqj4fHmM

Re: Gear Ratio & Tire Size Options For A D600?? [Re: E-Ticket] #1641784 08/10/14 12:35 AM 08/10/14 12:35 AM
Joined: Dec 2005 Posts: 1,156 Cruising! Q QuickDodge super stock
QuickDodge super stock Q Joined: Dec 2005 Posts: 1,156 Cruising!	Thanks for the pictures of your truck. It looks like a great old truck! Many years back, a knowledgeable Dodge truck guy told me there were a FEW overdrive 5 speeds used in the medium duty trucks. Unfortunately, most of the 5 speeds were direct drive in 5th gear though. Attempting to locate one of these rare overdrive transmissions might be nearly impossible. Of course, locating accurate information on such an unusual truck probably is not real easy either! I wonder if a transmission out of another brand of truck would bolt up to the bellhousing in your truck?

Re: Gear Ratio & Tire Size Options For A D600?? [Re: QuickDodge] #1641785 08/10/14 02:41 PM 08/10/14 02:41 PM
Joined: Mar 2007 Posts: 2,525 Louisville, KY E E-Ticket OP master
E-Ticket OP master E Joined: Mar 2007 Posts: 2,525 Louisville, KY	probably so because like in the 1994-2002 model 5-speeds, Dodge and Chevrolet shared the same transmission in the 2500 & 3500 trucks with the input shaft being the main difference. "Fat drunk and stupid is no way to go through life son......" http://www.youtube.com/watch?v=bK-Dqj4fHmM

Re: Gear Ratio & Tire Size Options For A D600?? [Re: E-Ticket] #1641786 08/10/14 06:44 PM 08/10/14 06:44 PM
Joined: Jan 2008 Posts: 4,255 Canada WO23Coronet master
WO23Coronet master Joined: Jan 2008 Posts: 4,255 Canada	What about a GV Overdrive unit? You'd have to mount it after the drum brake but do you think it would work? I think they're a .75 gear ratio, supposed to be very strong, used alot in RV's

Re: Gear Ratio & Tire Size Options For A D600?? [Re: WO23Coronet] #1641787 08/10/14 07:02 PM 08/10/14 07:02 PM
Joined: Mar 2007 Posts: 2,525 Louisville, KY E E-Ticket OP master
E-Ticket OP master E Joined: Mar 2007 Posts: 2,525 Louisville, KY	That is a thought..... I currently have the truck for sale but part of me does not want to turn loose of it and would seriously like to retain most of its originality for nostalgic reasons. Would like to change it over to a race car hauler or an enclosed race car hauler like back in the day when they were widely used. Our local track is 41 miles each way so it would be tough to justify a CTD change over other than the fact that it would be cool as hell to rumble through the gates at the track with a 12 valve under the hood..... Have been using it a lot lately to haul junk and tree limbs, etc to the dump and it is excellent for that but it tops out at about 60 mph. Would like to make it run 80 mph with ease so that I could drive it at 70 mph with out making it work for it...... "Fat drunk and stupid is no way to go through life son......" http://www.youtube.com/watch?v=bK-Dqj4fHmM

Re: Gear Ratio & Tire Size Options For A D600?? [Re: E-Ticket] #1641788 08/11/14 01:03 AM 08/11/14 01:03 AM
Joined: Jan 2008 Posts: 4,255 Canada WO23Coronet master
WO23Coronet master Joined: Jan 2008 Posts: 4,255 Canada	What kind of RPM are u turning at 60 MPH?

Re: Gear Ratio & Tire Size Options For A D600?? [Re: WO23Coronet] #1641789 08/11/14 01:12 AM 08/11/14 01:12 AM
Joined: Mar 2007 Posts: 2,525 Louisville, KY E E-Ticket OP master
E-Ticket OP master E Joined: Mar 2007 Posts: 2,525 Louisville, KY	Quote: What kind of RPM are u turning at 60 MPH? don't know....funny you ask....I was just thinking about that yesterday when I had it out for a dump run. Should have wired up a tach by now but just never did. "Fat drunk and stupid is no way to go through life son......" http://www.youtube.com/watch?v=bK-Dqj4fHmM

Page 1 of 2

1

2

Moderated by Al_Alguire, Hotwheelsjr, moparts, not_a_charger, RangerDan440, tboomer

Hop To

Powered by UBB.threads™ PHP Forum Software 7.7.1