Oyaji

I think it's one of the sweetest cars ever made, and to me the most beautiful, too. I've been in one of the 2 remaining originals, and have driven one of the replicas. I was so impressed I tried to raise enough money to buy the production rights, body molds, and tooling when they went up for sale about 20 years ago. Too bad I came up short. The fella who did get them raised the price and was successful when the market for them improved. If you're interested, look up "Beck Spyder". They are so light (~ 1,500 pounds) that they give very good performance with very little power from a flat-4... but if you toss in a 911 flat six, you can get a level of performance that ranges from scary to terrifying, depending on engine size and state of tune.

Skip to 4:04 for a description of the viscous coupling limited slip differential: http://www.youtube.com/watch?v=vFDZGAzApw4 I don't think I'll ever be putting in locking differentials (unless I get them for free!), but if there are cheap LSD axles (and transfer cases) to be had to replace open differential axles then I'd consider them for sure. Down here on the coastal plain, we are conspicuously short of both mountains and boulders, and since I have no plans to go seek out any to go bashing around in, I suspect low pinion axles wouldn't be a problem for my application... unless they wear out U-joints significantly faster even at stock suspension height because of greater driveshaft angles? What's the problem with low pinions?

I suspect so too. Shoot, I have an old 1967 VW Type 3 station wagon that has multi-port EFI. It's analog and not digital, but still EFI. :)

They aren't plentiful. Two, maybe three years ago I would see two or three fairly nice looking late model XJs on every independent used car lot I drove by. I haven't seen one in almost a year. There's a small used car emporium a couple of towns over that used to specialize in Cherokees. I looked at his web site the other day. Several Grand Cherokees, a bunch of other stuff, and two unspectacular Cherokees. Get 'em while you can. I'm going to keep my fleet running just as long as humanly possible. Seems there are more down here. Once you get away from the immediate coast, salt air isn't an issue for corrosion either, so we have plenty of rust-free vehicles down here. I started accumulating my "fleet" a few years ago - so far I have 3: an 86 2.5 4x4, an 88 4.0 2x4, and a 92 4.0 4x4. I was getting them mostly just for the axles (and other parts too), but since they are all still complete maybe I should think about restoration one day instead.

yes i meant D44 sorry about that. I figured that a 249 and axles out of a 5.9L ZJ Quadratrac would be easier to fit in, but since you said the XJs are better I will look into that direction. doesnt the 5.9 ZJ QT axles have limited slip system? compared to selectrac on the XJs of course. on my other thread someone had mentioned the 242 as well, I do like selec-trac but they lack limited slip, so far I've found the 249 will bolt onto the AX15 given that it has a short input. and theyre all 23 spline. all i need to know is about the driveshaft lengths for the 249. if the same I'll grab one. I'm a fan of Quadratrac, they saved my @$$ several times by surprise. besides in Missouri the DOT does horrible work plowing snow, so there are patches of snow/ice still on the highway while most will be dry. it would save me the effort of having to shift from 2wd-4wd. even offroad i prefer the 249 over the 242 i have several options for the crossmember. either a new crossmember from rustys, a TJ trans mount, or a tcase drop kit. i will research more on those after ive made my decision on the tcase. Comanche_Fanatic, I am intrigued by your proposed choices. I can tell you have put some thought into deciding for the ones you are making, and wonder about the reasons behind them. Sounds like you are mostly worried about combination high- and low-traction highway driving conditions. If this is so, I can see why you are attracted to having limited slip in both transfer case and axles. With regard to the limited slip viscous coupling in the transfer case, wear leading to failure and expensive replacement is doubtless tied to the frequency and severity of duty imposed on it. Seems reasonable to me to think that it might give good service if I understand the demands you expect to place on it. Same reasoning applies to your choice of axles. I am unfamiliar with the running gear you are considering, but since my needs for 4WD would seem to make similar demands on the drive train that you propose, I have a special interest in your progress. I live in flatland country, 2 miles down bad dirt road for which 2WD is fine but when pulling a load makes 4WD very useful. I need to get through muddy fields daily for about 12 weeks of the year and across beach sand infrequently all year, in both cases going repeatedly from high to low traction surfaces. Furthermore, I find bigger rear brakes and potential to modify for ABS very desirable. The combination of price and availability will also be factors in my decision. I think what you have picked out for consideration is something I should consider as well.

No, actually the viscosities are quite similar (go have a look at the chart I posted above). The method of checking viscosity is different for motor oil and gear oil, thus the apparent difference when comparing the numbering of the two. The main difference is the additives, as you mentioned. Here is an excerpt from the Redline PDF that Zack linked earlier that mentions why this is important: All oils are slippery, and with most lubricated components, the slipperier the better, but this is not so with manual transmissions. The synchronization of shifting gears requires friction to transfer energy from the synchronizer, which is locked to the input shaft, to its mating surface attached to the gear to be locked in as the drive gear. Few modern transmissions use sliding gears to change gearing other than for reverse gearing. Synchromesh transmissions have the gear pairs constantly in mesh. The drive gear is selected by using the shift forks to slide a synchronizer ring, which rotates at the same speed as the input shaft, in contact with the selected drive gear. Once the drive gear is brought to the same speed as the input shaft, the locking ring on the synchro assembly is allowed to slide over and lock into the drive gear. The time this process takes depends on how easily the synchro ring moves and the rate of frictional energy transfer between the two synchronizer surfaces. Higher viscosity lubricants slow the sliding of the synchro ring on the input shaft and require a longer time for the oil to be squeezed out from between the mating synchronizer surfaces. After the lubricant is squeezed out, the coefficient of friction of the lubricant determines the rate of frictional energy transfer between the two surfaces. Slippery lubricants such as hypoid gear oils can take too long to synchronize the gears, which promotes synchronizer wear. Red Line MTL and MT-90 has a coefficient of friction which is greater than conventional oils, allowing a quicker transfer of frictional energy. The graph below shows the desirable friction curve demonstrated by Red Line MTL compared to conventional lubricants. Note how the coefficient of friction is greater for the MTL than all others except the motor oil. Some motor oils have an adequate dynamic coefficient of friction, but most have problems with the static and low velocity coefficient of friction which can result in clashing. Clashing of the gears (actually clashing of the synchromesh gears, since the drive gears are always in contact) can occur if excessive shift effort is used in order to shift the locking ring into place before the surfaces have achieved equal speed. It may also occur at the end of a reasonably smooth shift if an instability exists in the coefficient of friction, causing stick-slip to occur. In this form of clashing, the ring slides on the mating synchro gear, but a sudden slippage causes a grinding of the gears. In order to prevent stick-slip from occuring and the gear clashing which results, the coefficient of friction should inflect downward as the relative speed drops to zero. http://www.redlineoil.com/content/files/tech/MTL%20and%20MT-90%20Tech%20Info.pdf The bit highlighted in red above I found the most interesting difference in the results offered by motor and gear oil. Note the mention that "some motor oils have an adequate dynamic coefficient of friction, but most have problems with the static and low velocity coefficient of friction which can result in clashing." Too bad they don't mention just which motor oils are perfectly acceptable - because their [Redline's] implication is that *some* are! I guess one solution would be to try a given motor oil in a gearbox and see the results for yourself; if you experience either clashing of the synchromesh gears when making fast shifts or stick-slip clashing when shifting normally, change to another brand, but if OK, then run with what you have in it. If you do go this route, please post your results. :) (Incidentally, I saw an earlier mention in this thread that motor oil was specified in the owners manual for some model years - was any particular brand of motor oil specified? I know that there are some very basic differences in how motor oils are formulated, which vary by manufacturer. One that comes to mind is the Castrol brand, which iirc is "parafin based", whereas other brands are "mineral oil based". It could be that the base makes a fundamental difference in the curves of their respective coefficients of friction. I'm sure there must be at least one SAE paper written on the subject, if anyone is interested in pursuing this further... but right now I am about tired of researching the subject!) There is a nice graph comparing coefficients of friction for motor and gear oils in the PDF that is worth a look, but I couldn't get it to paste here so if you want to see it you'll have to follow the above link. Here is some more info from the site I linked earlier worth a look - the entire page is worth reading too, for that matter: Automotive Gear oil chemistry differs considerably from motor oil chemistry in the types of anti-wear additives that are used in the formulations. Motor oils rely upon a Zinc-Calcium anti-wear structure, and Gear oils generally rely upon a Sulfur-Phosphorus anti-wear structure. (Considerable other differences exist in each of the types of fluids as well). Temperature and pressure activate the chemical EP (Extreme Pressure) components in gear oils. This chemical reaction provides slippage & protection to the gear face. Gear lubricants have a very distinctive odor associated with them, and this is generally due to their additive structure. Many gear oils maintain chemistry to reduce chemical attack of soft metals, and when the consumer selects a product, they should always be aware of what type & specification of lubricant the equipment manufacturer recommends for the application. One important thing to point out with gear lubricants is that they are not classified on the same viscosity scale as crankcase motor oils, and their viscosity relationship (not Load Carrying Ability or application read-across) may be approximately summarized as follows, 75w90 gear oil = 10w40 motor oil, 85w gear oil = SAE 30 motor oil, 90w gear oil = SAE 40 motor oil. The chart gives an accurate visual relationship of viscosities of different oils that are typically used for gear lubrication. http://www.torcousa.com/innov-lub-101.html

The stock SD22 naturally-aspirated engine is pretty weak at just 65 HP, according to the Wiki article, but I expect the turbocharger adds a fair bit of kick. What I found attractive about this setup is that the seller has already done all the work: it is complete and ready to bolt in... and he claims 42 highway MPG with it in his XJ. Such would just make me wave and smile all the more at the traffic zoom-zooming by me. :D I wish I could be so lucky as to find a similar setup for sale at similar price within 500 miles. I sure think it is worth a hard look, and if it seemed all the seller claims, I'd buy it if I were you, Jim.

"Okole" is Hawaiian for "anus". The company catered to mostly surfers who needed a seat cover that would handle daily exposure to passengers dripping wet with salt water, so they chose neoprene wetsuit material for their construction. Though I never bought any products by Wet Okole, my experience with wetsuits makes me think that seat covers made from that material wouldn't hold up to long use before delaminating - I'd guess a year or 2.

Worth reading, the accompanying article can be found here.

Since seatbelt anchorages are a safety item (they even have their own regulatory standard for Europe, I am unsure about USA standards though), it is important to match the dimensions and qualities of the bolts used in every way in order to have confidence in them. Not only threaded length, shoulder length, head area and shape, but also hardness and maybe other things too are important considerations. Because of this and the fact that you wouldn't expect to remove them very often prompts me to suggest it would be best to just re-use the originals.

Wow - thanks for posting. I saw the writing on the wall back in 2000 when I consulted briefly in the film industry. After a private screening at Warner Bros. of a film I was working on, our small group was asked to leave so preparations could be made for the demo of a new Sony video projector. I stuck around and chatted with the techs who were setting up... and from what I heard from them and saw of that first-generation projector, I knew the days of film were numbered. That caused me to drop my foray into the film industry after only 6 months. I never considered the implications for drive-in theaters until you started this thread. Thanks again for making me aware.

One other potentially-useful item: back in the 90s, a colleague who worked in lighting design told me that adding a capacitor behind any regular headlight would yield about a 25% increase in brightness. He said it was because there is still some un-rectified residual AC from the alternator flowing through the 12V DC system, and that adding the capacitor would make it available to boost the power of the headlights. I never got around to trying this, and I kick myself for not asking him what size capacitor to add. Maybe someone here with more experience in electrical systems could make a recommendation.

No experience with the square housings, but as Alex mentioned above about his experience with the Hella round housings in his Wrangler, I was shocked at the improvement using them in my 914. The cutoff is abrupt, so with proper aiming of the lights oncoming traffic has no problem being dazzled... and the light with 55W H4 bulbs is such a drastic improvement that "amazing" is a barely sufficient adjective to describe the difference from stock sealed beams. I never got around to adding the supplemental harness, but when I do I'll go with 100W H4s. I wouldn't be surprised to find the same level of improvement yet again, and I expect the night-and-day difference in the cutoff zone to make the double-power H4s quite acceptable to oncoming traffic.

I don't really follow all you are saying... but it sounds like you have a problem with your browser and/or computer. How many webpages to you usually have open in your browser at the same time? Maybe if you are running out of RAM you would get this problem, but geez, I have 21 webpages open in Opera (my main browser), and 5 more open in Firefox, plus video playing on Media Player too, and I have RAM to spare and no problems to report... Maybe it is a browser problem?Try restarting your browser and make a test post in the Test Forum while you have PhotoBucket open at the same time on another tab in your browser. If you still can't succeed, maybe reboot your computer and try again? Finally, is your browser up to date? If not, try patching it to the latest version your computer will run (make sure to set a restore point so you can roll back to your current version if you run into problems with the new version), then try again...

Jim, have you tried opening CommancheClub on one tab in your web-browser, then opening another tab in the same browser for PhotoBucket?

Now that is creative. Good luck with sales! Don't forget to finish your fuel-tank bung and bracket jigs, though! The finished products will be small enough to go through the mail, too, you know...

Actually, yes, yes I have. Back in college days when I broke the clutch cable on my 914 and the replacement took 6 weeks to arrive, I drove daily to school 47 miles each way (a third of that in town) with no clutch. It taught me the art of "strategic parking": seeking out parking spaces with a slight downhill so the car was easier to push fast enough so I could slip it into first gear with the engine running. Already knew the art of driving without ever touching the brake pedal (from driving 32,000-pound GVW trucks, overloaded with no functional brakes, starting at age 12), reading the traffic and signals far enough ahead so I didn't need to stop... Thanks for triggering those memories! :) That experience also prompted me to fashion a dirt shield to protect the clutch cable at its exit from the sheath from abrasion by the dirt and mud that accumulated from driving down 2 miles of bad dirt road in all weather just to get to the nearest paved road. Thinking outside the box is often the source of inspiration for novel solutions to problems never considered by engineers responsible for the original design, and I encourage everyone to share as much as they are comfortable offering (wouldn't want anyone to jeopardize any possible profit opportunity by undermining "patentability"!), regardless of how simple or off-the-wall they may seem at first glance.

I like reading your posts because you often come up with unusual solutions by thinking "outside the box". Whereas most folks just change parts, you look at the bigger picture and try to find a fix for the underlying cause for failure, as you did here. Thanks for sharing.

Thinking of posting a video (funny, but ultimately too much an invasion of privacy) - 180,000 mile engine, no idea of its previous history beyond the fact that it wasn't registered for over 3 years (and I believe the story that it never ran since then). Gas tank has holes rusted through it, and the remaining metal is so thin I poked my fingers through it in the 2 places I tried. Dry compression numbers average - 80, 85, 83, 80, 78, 95; wet - 95, 105, 103, 108, 95, 125. It will start and run... but only on 3-4 cylinders. *sigh* I may fiddle with it and get it running before pulling it down (when I get time - as you might guess I have a lot of other things taking up my time just now). I have a suspicion that at least part of its low compression is from having stuck piston rings from having sat without running for so long... which still begs the question as to just what was the reason that it sat for so long.

Indeed - but I wasn't referring to heat damage to the block, but rather heat damage to rings and pistons which then cause abnormal wear on the block. Whereas it takes a LOT of heat to affect the block directly, it doesn't take as much to de-temper the rings and collapse the piston skirts... which then start nibbling and scrubbing away at the cylinders. You guys have no idea how pleased I was to hear that the Renix block is high-nickel cast iron, and accounts of sometimes still being able to see the original hone marks in the cylinders. That reminds me of old Datsun engines I rebuilt years back, whose high-nickel-content blocks showed little wear and often still-visible hone marks when torn down after 200,000 or even 300,000 miles.

Can't see much of it, but that there looks like a positive-displacement Roots blower. If so, that means power on tap, with no lag whatsoever! I sure am curious as to price and what modifications to the fuel and intake system are required to make it work. Hoping you post full details and many pictures, plus video. :)

Now that was clever. :rotf:

The Renix-era engines are not prone to overheating. The problem is that owners of Renix-era XJs and MJs do not understand the "closed" system. They let the radiator get clogged, or they don't understand that the plastic bottle on the firewall is a pressure vessel and that, if it's leaking, the cooling system isn't working. The engines themselves are no more prone to overheating than any other generation of the AMC I-6. Errrrm... that's exactly what I was guessing and tried to make clear. The biggest problem is that all these trucks are over 20 years old now, and unless you are the original owner, you cannot vouch for how any individual example was operated and maintained. Considering how unusual the closed cooling system is to the general public, seems to me that unfamiliarity with it has led to a number of avoidable overheating events. That's just the sort of thing that takes the temper out of rings and collapses piston skirts... which loss of tolerance leads to excessive and premature cylinder wear. :(

"Raping"? That's more than a bit disturbing... I'd be freaking out too if my engine was making these sounds! :yes: Seriously though... can you identify the frequency? Crankshaft noise is the same frequency as the engine RPM divided by 60, and is indicative of an engine on its way out. Camshaft noise is only half the crankshaft frequency (because it only turns half the speed of the engine) and may not be particularly bad at all. Pretty common is valvetrain noise caused by worn stamped-steel rocker arms, which are pretty cheap and easy to replace...

Carnuck gave good info about terminals and connections. Just because they look good doesn't mean they are good - check to be sure. The fellas who suggested rapping on the starter gave a good tip too. As a starter gets older, particles from wear accumulate, and the brushes themselves get shorter. The combination of the 2 can cause the brushes to hang up when the pressure of the springs that press the brushes to the commutator becomes insufficient for the brushes to make good contact. Rapping the starter is sometimes all it takes to get the brushes to make good contact... but don't depend on this too many times - you can ruin your starter by using it with worn-out brushes. Pull it, clean it, and replace the brushes at first opportunity. Jim gave the best advice for troubleshooting the starter itself. Do the above, then run his simple tests, then remediate appropriately.