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Discussion Starter #1 (Edited)
In all fairness the axles are 36 years old. It's the left axle shaft that's twisted. The right axle shaft only shows wear on the splines. Probably have over 300,000 miles on them. I've only driven it for the last 16 years with the 4BT.
I don't dump the clutch, I don't power shift. Must have been metal fatigue?
The rear axle was rebuilt 5 years ago. Just after that the upgrade to the turbo and extra fueling began. I'm picking up a used axle shaft tomorrow.
Love that low end torque.

And I just sold my 92 Dodge D60/D70 combo with 4:10 gears.:(

When I put the automatic (46RH) in the Scout that will take care of the shock loads, no more problems.

edit: these are rear axle shafts.
 

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that 44 can be built up stronger---i have a friend running a pulling truck--79 ford with 2 blown big blocks (on propane)---front engine runs the rear--backwards rear engine runs the front----the front dana 44 has been trouble free--the rear ford 9 inch has been shearing pinions......
 

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Discussion Starter #3
that 44 can be built up stronger---i have a friend running a pulling truck--79 ford with 2 blown big blocks (on propane)---front engine runs the rear--backwards rear engine runs the front----the front dana 44 has been trouble free--the rear ford 9 inch has been shearing pinions......
Forgot to mention these are rear axle shafts.
I checked in about custom shafts, the kit was $440. Picking up a used axle today for $50.
 

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Forgot to mention these are rear axle shafts.
I checked in about custom shafts, the kit was $440. Picking up a used axle today for $50.
!! are the " bean counters" in charge ;)
 

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I'm trying to decide on my front axle right now. I read and hear stories like these and think the D44 can last fine if you aren't sled pulling or rolling huge tires. I have 410 gears and need to go to 355. Debating to beef up and overhaul the D44 while I change gears or just spend it toward a D60. The 355 gears will engage more pinion teeth which should help the D44 at that break point. Same 30 spline as the D60 in the rear I believe. I'm pulling my gasser and thought it would be the best time to work the axle. I have a high pinion D60 housing but it needs shortened, perches, all the guts etc. I have a single cab 77 F250 with 84K original miles and just looking for making a reliable all around driver and moderate off road. Hate to blow the budget but doing this twice will be more $$.
 

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What size tires? I've put hundreds of thousands of miles on my scout rear 44 with a 6BT pulling trailers all over and had no problems with axle shafts so far...… I'm running 235/85r16s. Spline wear might be a sign of tube alignment problems..


I did just have a problem about a month ago with my ring gear bolts coming loose......
 

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It could be there a difference in the torque pulses of a 4bt and a 6bt. The 6bt is not nearly as hard on parts as the 4bt. Gear Vendors will recommend using their OD unit with a 6bt but not a 4bt. The 4 cylinder will destroy it.
 

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Discussion Starter #10
What size tires? I've put hundreds of thousands of miles on my scout rear 44 with a 6BT pulling trailers all over and had no problems with axle shafts so far...… I'm running 235/85r16s. Spline wear might be a sign of tube alignment problems..I did just have a problem about a month ago with my ring gear bolts coming loose......
As far as I know those are the original axles, 36 years old. Tyres are 33/10.50,15s. I'm not complaining.When the auto trans goes in to replace the manual I expect that will be the end of twisted axles. And because of the smoke at home altitude I've had to detune the engine and I'm still not happy with the smoke. Too busy with other project to really apply myself to the fix.
 

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Scout, I've always wondered if an oxygen injections system could be devised for you guys at high altitude. The do nitrous systems but you just need a little more oxygen at the high altitude. Of course, riding around with a couple big welding tanks in the back may not be too practical. You'd need a system that metered based on altitude so when you descended to a lower level it would eventually cut off.
 

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Discussion Starter #12
Char1355, Without going "Electronic" I think the best bet is a well thought out set of compounds. How about a hx25 for the small turbo, for the large turbo he221 with a 7cm2 exhaust or larger. This is a brainstorm have no idea if its even practical, so lets kick it around. First problem is to make it behave when I drop down to sea level and back up to 4K plus. Any ideas on this if this might work?Remember the scout is a work truck.
 

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An HE221 would be way too small for a compound set up primary. The combo that has proven its metal has been an HX30W paired with an HX35W. With higher altitude you need to move move volume of air to get more oxygen. The HX30W with the 44mm inducer is about ideal as a secondary. The stock 40mm unit can work well too. The HE221W would possibly be an alternative secondary. Another primary that can be used is the Super HX40W. In higher altitude it might do very well. Member Eggman is running twins at high altitude and he can tell you what works.
 

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Scout I'm running what turned out to be the 42mm hx-30 which I added a 6cm exhaust housing to with a wh1c and the combo works well once I got then dialed in, I finally settled on the gate on the 30 opening at 36 psi and on a long grade will see boost creep to ~ 40 psi.
Boost comes on early and from 20 to 35 psi happens in a couple of seconds at speed, with the gate set where it is to get those numbers at 4,500/5,000 feet it does not make excessive boost when I'm down at 500 foot but it does come on quicker but the waste gate on the 30 still controls it just fine. I do not have a gate on the wh1c but I'm sure that a gate on it would give even more control over things, If you have the room I would go compounds and never look back ;)
 

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Good info Steve. That 42mm HX30W is kind of an odd duck. It was a 6bt industrial turbo that came with the 12cm gated turbine housing. We don't see a lot of those, but one does pop up every now and then. Perfectly good turbo for the 4bt once you change to the 6cm turbine housing. Best alternative would be the 44mm. Your WH1C is essentially identical to an HX35W. Same size compressor and turbine but with a different method of attaching the compressor housing. I have one of those in my collection too.
 

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Discussion Starter #16
If the HE221 is supposed to be one of the fastest spooling turbo(s) with the 6cm2, which is on the Scout now, how does it spool faster in a compound setup to prevent smoke?Good news is In my pile of stuff I should have a H1c from a 91 Dodge ctd probably has a 18cm2.
 

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I have the 12cm on the wh1c
 

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Scout, it's not that the secondary turbo will spool any faster, but with the help of the primary there is more total boost. If you have smoke in the lower RPM range with an HE221W, it sounds like you have too much fuel. Either the pump turned up too high or injectors that are too big. Smoke makes no power. The leaner you run a diesel, the better. Now if you have smoke down low and the primary turbo kicks in I'd bet the smoke disappears because you have enough air to burn it. Everyone who has done twins always has a bit of adjusting to get it just right. When it's spot on there's virtually no smoke anytime. EGT's are very low and the power seems dramatic. Although the HE221W is a super good turbo, the 44mm HX30W shows to be the ultimate in a normal twin set. That mated with an HX35W with a 14cm turbine housing. The 18cm H1C may do OK. Might be a bit slow to come on. A Super HX40W only has a 16cm turbine housing. Twins turn into a real balancing act of turbos and fuel. When they are right it is magic.
 

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I ended up modifying my stock fuel pin, using the side with the shallowest taper I removed enough material from the top half that at the top it allowed ~ .045" more follower travel that it had on the steeper side.
I am also using a boost fooler elbow in the AFC line.
 

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Discussion Starter #20 (Edited)
I've done all the mods to prevent excessive smoke, custom fuel pin, elbow eliminator, bleed off, metered flow to the android, star wheel maxed out on (up) on spring pressure, Injection pump and Stock injectors have been rebuilt. Timing advanced to 1.37mm. In Phoenix at 1200 with the fuel turned in approximately 2 full turns smoke was minimal with these settings, every thing worked good. Now at 4400' I've had to lean the main fuel 1/2 turn and i still have excessive smoke on the low end, the skinny pedal is not near as much fun.I'm thinking a bit more advance might help.Tuning:Vid of dyno run (smoke!) https://flic.kr/p/24NAFfB...........edit; or go with a P pump.
 

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