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Discussion Starter #1,121
Yes all the gauges work fine except for the Tach and Speedo. There is no option for a Mechanical Tach. Even if I could find the drive there is no way to route the cable at this point and then finding indicator would be nearly impossible.

I will get these, or I think the replacements, to work for sure, I just have to wear them down until they submit.

There's a new video up on Youtube with me doing a walk around describing the vehicle. https://www.youtube.com/watch?v=5ypPMfYOgNk&t=3s

Randy
 

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Discussion Starter #1,122 (Edited)
Breaking News !!!

I got the Speedo to work!!!!

I had to take the Speedo Drive Unit off the back of the Transfer Case to fix an oil leak which I got into last night. Before I put it back in, I called AA and asked some questions..

The Speedo Drive Unit has 4 slots cut in the face and I was under the impression that they were there so the Yoke Clamp would fit it's tabs into those slots and stop any rotation from occurring.

Point being,,, that the Speedo Drive Unit which has an eccentric hole for the gear shaft that engages the output shaft of the Transfercase was not rotated into the output far enough to engage the gear to the output shaft. IE: it wasn't turning.

When I put it back together I used a Square Deck Screw Driver to wiggle the shaft back and forth so I could tell when it engaged the output shaft. The Yoke Clamp's tabs were no where near those slots when I got done and now it works!

How about that?

The Pic shows the previous location of the Speedo Drive Unit before I fixed it. It is about 45 degrees past that now.

Starting to think the Tach problem might be a similar issue with the sensor not close enough to the Ring Gear to get a good signal. I'm dreading that job!

Randy
 

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are you running a conventional parking brake at the wheels or just the transfer case brake? If so why not just restore the original park brake system vs going with the transfer case brake system?
 

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Discussion Starter #1,124 (Edited)
Smoothoperator: There was no "Original" Parking Brake System. This vehicle is totally built from Scratch. The Rear Brakes are 3/4 ton GM Discs with Chevy Malibu Calipers. There is no E Brake on those calipers. The Transfer Case mounted E Brake,,, is the E Brake. It works great. The Trans also has a Parking Pawl.

More "Breaking News" I have officially calibrated the Speedo using mile markers on the highway that runs by my house. It is close but still needs some refinement. AS soon as I get my GPS back in action I will use it to refine the Speedo readout. It seems a little slow based on my Seat of the Pants readings right now and Changing the calibration is pretty simple..

I am now totally sure that the Overdrive Gearbox is in Direct, not OD.

I also will need to get the front end professionally aligned as there is quite a bit of shimmy and wheel wobble as it is. I aligned it with a Tape Measure so it is probably not exactly right? Maybe?
 

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Randy, on the tach sensor, the general rule of thumb is it should be about the thickness of a credit card from the gear. Glad the speedometer is functional now. I suspect the tach is just an adjustment issue.
 

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Discussion Starter #1,126
Char: the Proximity Sensor has a body with 16 pitch threads (3/4-16) one turn = .0625. The instructions said 1/2 turn off the Ring gear which is what I think I set it at. I may have done one full turn as I think they told me that over the phone once. Point being I don't know exactly what it is.

The owner of Isspro told me they need to be 1/4-1/2 turn off the ring gear so in the event I don't have it adjusted right that should fix it.

However the Tach Needle never moves off its power off position at 6:30 even when I turn the key on. The Speedo does a full sweep when powered up and we can't figure out why the Tach doesn't. They are testing one in the lab today to find out if it acts like mine or the way we think it should work.

Going to try to get into my favorite Front End Shop today and see if I can get the front end to act right.

I drove around for an hour and half last night and put 50 miles on the car. It is not too bad to drive and with a little more refinement it will be quite nice to drive.

Will tackle the O/D Switch this weekend as I am now sure that the O/D is in Direct as it sits.

Randy
 

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Discussion Starter #1,127 (Edited)
Fan Belt Failure!

So Friday night I was out for my nightly cruise of Downtown Ojai CA.

I first went to my local Gas Station to clean my windshield and decided to check under the hood. I found the top radiator hose seeping juice so I tightened that clamp a few more turns. Closed the hood and took off.

Just as I got to downtown I looked down and saw my Temp Gauge at 220F!!!! Yikes!!! and pulled into a market. I figured it just needed some water since I had just fixed a leak, so I got a jug of water. Came out and put water in when a friend who is a well know off road guy came by. He hadn't seen the Jeep for some years and was astonished at the progress. He also noticed that the Fan Belt was shredded. Damn missed that and,,, I can't fix that here.

So I called AAA and they scraped the Jeep up on the flatbed and took me home. The shame of being driven down Ojai Avenue at 8:30 on Friday Night with my Jeep on a Tow Truck,,, when the town is packed with tourists,,, was overwhelming. The ignominy of it all. Total Shame!

Got home and parked it. Got up Saturday and started looking for a Fan Belt for a 4BT,,, Non existent! I went to every Auto Parts store in Ventura and nobody had one. Carquest provided the quickest delivery on Monday, so I ordered one.

Went home and started checking alignment of the pulleys and everyone looked like it was lined up with every other one and then I notice that the Alternator was a little crooked? Then I noticed it was only hanging on by one bolt in the alternator mount that hooks to the Coolant Outlet. That's one out of 3 and it was half way out! Then I found that the lower bolt that secures the Alt on the bottom was broken off? The Alternator was literally flopping around in the wind like a rag.

So effectively the Alternator was hanging by one bolt which pretty much solved the question of why the fan belt failed. 2 out of 3 upper bolts missing, one almost gone and then one on the bottom broken off. I have to get new bolts from Cummins on Monday as well and they will be torqued down with a torque wrench and Loctited in. A Grade 8 bolt on the bottom with a Lock Washer as well.

I thought ISO pattern threads were supposed to tighten with vibration? Least that's what they've been pushing since the 60's, obviously not the case here!

I guess Engine Vibration is a serious issue here?, and it is obvious that every fastener on this car will need a Lock Washer, Lock Nut, Loctite or Safety Wire.

One of the reasons why I missed this while tightening the Coolant Hose Clamp is because the Coolant Overflow Bottle blocks your view of the front of the engine from the right side. Missed it as the Alternator is directly behind that bottle.

Missed the Fan Belt being shredded because the radiator is nearly at eye level and you have to stand tall to look over it.

Also brings out the need for a pre-flight inspection of the vehicle before each trip.

Oh well, finding the Bugs is what all this driving is about. Life goes on.

Randy
 

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Yea, that's exactly why you stay close to home and do lots of little trips. As far as the bolts needing Loctite I've only used Loctite where prescribed by Cummins, so far no fails.
 

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Discussion Starter #1,129 (Edited)
On another Note: While I was recovering from the part where the alternator was falling off, I decided to reset the Toe In on the Front Axle. After getting my wife to hold the dumb end of the tape I found that there was about 1/2" Toe Out! (1" difference between the front and rear of the tire. This would definitely account for the Front End Shimmy.

It now has @3/8" of Toe In. Big tires obviously need more toe in due to the rearward forces they create while driving. Each wheel and tire weighs @ 125 lbs.

Will test it out tomorrow when I get the rest of the engine put back together with new bolts and fan belt, and can drive it. Hopefully this will alleviate the need for a Shimmy Damper which I have never had to use before on Front Ends that were set up right..

Randy
 

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I got this tip from some stock car racers.

Longacre Toe-in Plates.jpg
Longacre Toe-IN Plates

https://www.summitracing.com/parts/lng-79501

TECH TIP: Once you have the plates centered on the tire, and tight against the tire, lean something heavy against the plate (centered). I have a couple of old F150 frond disk brake rotors for this. That allows you to use the tape measures and not worry about the plates moving.
 

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Discussion Starter #1,131
There is a really nice white line buried in the tread on both tires so we had a good reference point to measure to on each tire front and rear.

I have seen the toe in plates before but I doubt they are big enough to span 37" high tires. The other way is to clamp them to the Brake Discs, but then you have to take the wheels off and jack the front end up.

I think we got pretty accurate measurements this time.

Randy
 

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There is a really nice white line buried in the tread on both tires so we had a good reference point to measure to on each tire front and rear.

I have seen the toe in plates before but I doubt they are big enough to span 37" high tires. The other way is to clamp them to the Brake Discs, but then you have to take the wheels off and jack the front end up.

I think we got pretty accurate measurements this time.

Randy
Fresh tires that still have the white line - that should work fine.
 

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Discussion Starter #1,133
After getting the engine compartment back together I took the Jeep for a drive to assess the new front end alignment. DEATH WOBBLE big time !

I came back and adjusted the tie rod back 2 turns, and went out again. Less but the same. Came back and took one more turn out of it. Driveable,,, it currently has 3/16 of toe in, but the front tires are worn in a little so I will have to rotate them to the back and try that. Should run clean like that, but I see a problem with this in the future.

My Friend Cameron suggested a Panhard bar which I have been considering for a while. Part of the death wobble in jeeps has been the looseness of of the suspensions compared to other cars. They need to articulate so there is inherent looseness, and all Jeeps have had Panhard bars locating the axles side to side since the YJ's in the early 90's.

Considering options at this time. Will rotate tires tonight, need my sons 1/2" impact.

On another note: I still have some misalignment of the fan belt. I need to space the Alternator Pulley out about 1/4". any suggestions? There is no way to move the whole Alternator as the mount defines it's placement and it is hard up. I'm thinking a 1/4" spacer behind the pulley but don't know it the shaft is long enough that I can get the nut back on?

Randy
 

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>> I need to space the Alternator Pulley out about 1/4". any suggestions?

Delco 10si alt.jpg
Random Delco 10si from my stash. I measure the thread "stick-out" at approximately 0.08". Note a split lock-washer. 1/4" spacer, lock-washer and thread-locker? Or, since fan belts are flexible, split the difference with a 1/8" spacer? I don't have a valid opinion.

NOTE: If this is a Ford alternator, like on my 1986 4bt, the pulley has a tapered shim (I'm not a machinist - conical tapered wedge?) below the lock nut. It took 2 of the best independent mechanics 1/2 an hour to get the wedge free. Fortunately, one of the guys owed me big time - I was there with a truck when he needed to evacuate for a big wild fire.

p.s. If i remember correctly, you have a good caster set into that axle...
 

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Discussion Starter #1,135
I'll have to take it off and see exactly what there is to work with. This is a serpentine belt pulley.

it is causing the belt to run one tooth off the fan pulley which will eventually destroy it.

I figured that the belt would flex enough to maintain it's alignment but I was wrong and it will NOT stay in the Correct Groove no matter what. As soon as you start the engine it skips right off.

See pics you can see where the belt is running on the tensioner pulley towards the back when it need to run in the center. The belt runs from the top of the Alt Pulley, under the Tension Pulley and then over the Fan Drive. and the Alt Pulley is forcing it to run back too far.

Hoping there is enough material to work with to swallow a 1/4" spacer behind the pulley and I am not beyond counter-boring the front side of the pulley if necessary.

On another Note: I found the problem with my Front End Shimmy. There is about 10 degrees of slop in the Steering Gear! It came out of an old Chevy truck and I always figured it would need help but I never suspected it had that much slop,,, until I got onto the steering shaft and wiggled it back and forth. Definitely sloppy!

So the Pan Hard Bar Project is probably not needed,,, which is good a good thing as it was going to be challenging to say the least.

I've got to call Tommy Lee and see what it will take to fix my Steering Gear and amp up my pump to push these big tires around.

Randy
 

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>> This is a serpentine belt pulley.

OOPS, senior moment on my part - I was last working on a V-belt car. Serpentine belts do not like a third dimension.

That alt is definitely different that the Ford alt in my 1986 4bt. Looking at the fan, my guess is a Delco 12si or newer.
 

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Randy The most common cause of serpentine belt jumping a grove is the best tensioner not in alinement, usually from wear. Could it be you got a bad one?
 

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Randy, I was wondering whether you have the correct pulley on the alternator? Cummins had a large number of different pulleys depending on application. Was this alternator on the engine originally or added later? Is it a Delco 10si, 12si, 21/22si, or Bosch? Your pulley appears to be almost flush against the front fan and most that I've seen are spaced out a small amount.
 

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Discussion Starter #1,139
Char: This alternator came on the engine. If there is a pulley that is spaced off the front about 1/4" farther I'd buy it. It is a Delco Alt.

Trying to get a hold of Lee Power Steering in Valencia to rebuild mine, but if I can't get to them I'll get a Rebuild from NAPA. The biggest issue is getting the identical one from NAPA as I have no idea exactly what this one came off originally. I think it was a 70's Chevy truck but not sure. I need the angles on the sector shaft to be identical to what I've got now or the Pittman Arm won' t be in the right place and I'll have to start all over.

MY Water Temp gauge quit today and the EGT gauge is all over the place so it is wonkie too. Supposed to send the Tach back to Isspro so they can figure out what is up with it or replace it,,, and the other two gauges are going in the same box.

Lots of things going wrong all at once.

More fun to figure out? NO,,, just a PITB!

Randy
 

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Since your alternator is a Delco, it is most likely a 12si, but doesn't eliminate a 21si type. The 12si has a 17mm shaft. Here's a link for a pulley specified for a 4bt/6bt and that alternator. https://www.amazon.com/PREMIUM-ALTERNATOR-PULLEY-CUMMINS-ENGINES/dp/B014GNAS1W Not very expensive. The 21si has a 7/8" shaft or about 22mm. Pulley for that one is Cummins part 3918275. Don't believe you have that alternator because your mounting bracket appears to be the style for the Delco or Bosch units. Sort of strange that the pulley that was on the engine originally would suddenly be out of alignment. Are there any spacers in the bracket that might have been put back in the wrong position? My industrial catalog shows a spacer in the back of the bracket.
 
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