From owner-xj-digest-at-digest.net Sat Jun 25 22:29:53 2011 From: xj-digest xj-digest Sunday, June 26 2011 Volume 01 : Number 3295 Forum for Discussion of XJ cherokees and wagoneers Brian Colucci Digest Coordinator Contents: RE: xj: RE: fsj: Re: original tire size - 1963, conversion table??? xj: more tire tech info xj: O/T Any Datsun guys around? XJ Digest Home Page: http://www.digest.net/jeep/xj/ Send submissions to xj-digest-at-digest.net Send administrative requests to xj-digest-request-at-digest.net To unsubscribe, include the word unsubscribe by itself in the body of the message, unless you are sending the request from a different address than the one that appears on the list. Include the word help in a message to xj-digest-request to get a list of other majordomo commands. ---------------------------------------------------------------------- Date: Tue, 21 Jun 2011 12:38:28 -0700 From: Jim Blair Subject: RE: xj: RE: fsj: Re: original tire size - 1963, conversion table??? Probably powerlok > Date: Tue, 21 Jun 2011 08:32:07 -0700 > From: john-at-wagoneers.com > To: xj-at-digest.net > CC: fullsizejeeps-at-gmail.com; erniesilva-at-gmail.com; fsj-at-digest.net > Subject: Re: xj: RE: fsj: Re: original tire size - 1963, conversion table??? > > not always easy to find... or see... :) > > yep...limited slip, posi and lockers make it a bit more challenging... but > are nice to have, well not so much lockers... > > my '67 Wagoneer had a nice limited slip rear end... likely an auburn posi, hard > to say, likely factory... what was it back then? > > john > > > > ----- > ------------------------------------------------------------------------ > -o|||||o- > Snohomish, Washington - where Jeeps don't rust, they mold > http://AMSOIL.com/redirect.cgi?zo=283461 > http://JohnMeister.com HTTP://WAGONEERS.COM http://fotomeister.us > ------------------------------------------------------------------------ > > > On Tue, 21 Jun 2011, Jim Blair wrote: > > # All the Dana axles have the tag (front and back) from the factory. Model 20 > # rear used '80 to '87ish had a letter code stamped in the center housing next > # to the passenger's side axle tube. The ring and pinion have the tooth set (ie > # 49-18) stamped on the edge of the gears. Lifting one tire won't work if it's > # posi. 8^P > # > # Jim Blair, Lynnwood, WA '87 Comanche, '83 Jeep J10, '84 Jeep J10 > # > # > # > Subject: fsj: Re: original tire size - 1963, conversion table??? > # > To: erniesilva-at-gmail.com; john-at-wagoneers.com > # > CC: xj-at-digest.net; fsj-at-digest.net > # > From: fullsizejeeps-at-gmail.com > # > Date: Tue, 21 Jun 2011 14:51:37 +0000 > # > > # > If there is a data plate or stamping it will usually be on the left side of > # the cover. It could be in the form of the ratio, or list the ring and pinion. > # > > # > On my 81 it had the ring and pinion think it was 49 and 18. That works out > # to 2.7222. > # > > # > The other way of determining the ratio is to jack up one tire, transmission > # or xfr case in neutral, and rotate the tire one revolution, counting the times > # the driveshaft will spin. > # > If you have a limited slip this might not work. > # > > # > Or by taking the cover off, change the gear lube while you're at it, and > # count the teeth on the ring gear and pinion. > # > > # > Or you could take a known tire diameter, transmission in a 1:1 gear, drive > # at 60 mph with a gps, and measure the engine rpm and use the formula on my > # server, or some variation of this. > # > > # > > # > *** john at http://wagoneers.com *** > # > > # > -----Original Message----- > # > From: Ernesto Silva > # > Date: Tue, 21 Jun 2011 09:35:09 > # > To: john > # > Cc: xj-list; full size jeep list > # > Subject: Re: original tire size - 1963, conversion table??? > # > > # > Well...mmmm..., I don't recall what I had for breakfast, so your > # > memory may be fuzzy for you but it's superb for me, ;) > # > > # > I don't know the gear ratio, I can remember some note on my J100 > # > manual about a plate bolted to the rear axle center "ball", I'll have > # > to take a look at it, maybe in the weekend (I leave home at 8AM and > # > get back at 11PM in working days). > # > If the plate it's not there then I can lift a wheel and put it into > # > neutral so I can rotate the transmission axle and count turns till I > # > have a complete wheel turn, maybe I'll have a half of the ratio or > # > double of it. > # > > # > I'll tell you the ratio when I get it. > # > > # > Thanks for your "lesson". > # > > # > Ernesto. > # > > # > > # > On Tue, Jun 21, 2011 at 1:43 AM, john wrote: > # > > the original size in 1963 was: 6.70 x 15, later changed to 7.10 x 15 4 > # ply rating. > # > > > # > > I'm not sure what this translates to for today... if your tire diameter > # is about 29.5 > # > > inches that would equate closely to the current 30 x 9.5 x 15. (29.3?) > # > > > # > > I got the original size information from Robert C. Ackerson's book The > # Standard Catalog of Four Wheel Drives. It is > # > > a superb work, well documented and very rarely do I find any errors in it. > # He has written several > # > > books, most popular is the 50 year jeep history... My copy of the Std Cat > # of 4x4s is well worn, have a newer > # > > edition as well. > # > > > # > > > # > > In 1967-8 he cites 7.75x15, with the super wagoneer 8.45x15. Later I see > # 10x15... I don't > # > > remember when tires changed from numbers to letters to the metric... I'm > # sure someone will be > # > > able to provide a link to the exchange ratio. :) > # > > > # > > I don't usually guess, I try to look information up. If I'm not sure, > # I'll say so. > # > > that said, from memory, a 235/75r15 is about 28.9 inches, 30x9.5 about > # 29.3, a 31x10.5 about 30.3, > # > > give or take a little bit. I have it on my server in axle calculations.. I > # should be within a half an inch on each of these... > # > > > # > > these are also the three tire sizes I typically work with on my jeeps... > # xj and sj. > # > > > # > > although on this white j10 I may go undersized to help it out around > # town... > # > > > # > > > # > > also in 1963 they used 4.89 gears, with 3.73 and 4.27 optional. the '67 > # -'70's that > # > > I've owned were usually 3.73 gears. what's yours? > # > > > # > > > # > > john > # > > > # > > > # > > > # > > ----- > # > > - ------------------------------------------------------------------------ > # > > -o|||||o- > # > > Snohomish, Washington - where Jeeps don't rust, they mold > # > > http://AMSOIL.com/redirect.cgi?zo=283461 > # > > http://JohnMeister.com HTTP://WAGONEERS.COM http://fotomeister.us > # > > - ------------------------------------------------------------------------ > # > > > # > > > # > > On Tue, 21 Jun 2011, Ernesto Silva wrote: > # > > > # > > # Does anyone knows which is the original tire size for a '63 Wagoneer? > # > > # > # > > # I've been looking at those tire diameter calculation web pages for 2 > # > > # seconds until I decided to measure it, about 75 cm or about 29.5 > # > > # inches. > # > > # > # > > # Now I need to know the original tires diameter so I can get the ratio > # > > # and calculate the "real" speed when the needle hits 80 Kmph. > # > > # > # > > # Regards, > # > > # Ernesto. > # > > # > # > > # On Mon, Jun 20, 2011 at 8:00 PM, john wrote: > # > > # > the '83 J10 is supposed to have: 225/75/15. > # > > # > > # > > # > it has 265/70/16's > # > > # > > # > > # > supposed to be 28.3 OD - is 30.6" OD - that's a 8.2% error > # (calculated 9.x %...) > # > > # > > # > > # > if I stay with 16" rims I could run a 205/75/16 to be 0.6% too > # fast... :) > # > > # > > # > > # > if I go smaller I will increase my gear ratio which will be better in > # town, but I'm concerned about > # > > # > going too small... smaller tires will also bear less weight... 2.72 > # gears really stink, unless > # > > # > you're trying to set a land speed record or something... not sure > # what Jeep was thinking using these ratios. > # > > # > sure it's only turning about 1900 rpm at 60mph.. but getting to 60mph > # requires a small oil tanker and a sundial... :) > # > > # > > # > > # > john > # > > # > > # > > # > > # > > # > ----- > # > > # > > # ------------------------------------------------------------------------ > # > > # > -o|||||o- > # > > # > Snohomish, Washington - where Jeeps don't rust, they mold > # > > # > http://AMSOIL.com/redirect.cgi?zo=283461 > # > > # > http://JohnMeister.com HTTP://WAGONEERS.COM http://fotomeister.us > # > > # > > # ------------------------------------------------------------------------ > # > > # > > # > > # > # ------------------------------ Date: Tue, 21 Jun 2011 12:54:49 -0700 (PDT) From: john Subject: xj: more tire tech info found this page, with tech info provided by one of the early list members: http://wagoneers.com/FSJ/tech/TIRES/tire-calcs.html ----- - ------------------------------------------------------------------------ -o|||||o- Snohomish, Washington - where Jeeps don't rust, they mold http://AMSOIL.com/redirect.cgi?zo=283461 http://JohnMeister.com HTTP://WAGONEERS.COM http://fotomeister.us - ------------------------------------------------------------------------ ------------------------------ Date: Sat, 25 Jun 2011 22:29:22 -0700 From: Jim Blair Subject: xj: O/T Any Datsun guys around? The '84 Datsun 720 2wd king cab with Z24 motor and 5 speed I'm about to part out is at my cabin 50 miles away right now so I can't see it. Trying to recall if the motor is front, center or rear sump oil pan. I found a '78 B210 fastback needing a motor and I was thinking the Z24 and 5 speed would be a good swap in (I did it years ago when I was just starting out as a wrench with an L18 and 4 speed with 510 wagon diff) I tried the forums, but they seem to be dead. Written laws are like spiders' webs, and will like them only Entangle and hold the poor and weak, while the rich and powerful will easily break through them ANACHARSIS Scythian philosopher (fl. 600 BC) ------------------------------ End of xj-digest V1 #3295 *************************