Noise from front diff/ transfer case after gear install

[pcrawfordpt]

Shop believes that they have found the problem. I have screwed up my front driveshaft, and installing the gears made everything worse and I broke this joint when I put it in 4WD. I do NOT believe this was the shops doing. I drive my Jeep exclusively in sand and snow. BUT I drive it at 10/10s like a rally car, not joking. On my last outing, i de-beaded a front tire and unloaded my jack by mistake at camp, and had to drive about 1 hour back to camp through sand dunes on 3 wheels, at RPM REDLINE to get through some of the dunes. This could not have been good for Jeep.

Yep….thats an issue. I did put in a new JE Reel driveshaft when I installed my suspension Lift.

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[818Gladiator]

Shop is sending me quote to upgrade driveshaft now. Let’s see what the damage $$$ is

 

[818Gladiator]

Yep….thats an issue. I did put in a new JE Reel driveshaft when I installed my suspension Lift.

Thank you for you help, you insight has be useful

 

[OHJeeper]

after thinking about it…
YES, the ECU of the truck has a setting inside/ option to change the gear ratio of the differential. However this has no bearing on the actual jeep, as it’s a Base Model Manual 6-speed. There is no TCM. Where would the ECU be sending any signal to?

There are a number of sensors in the manual transmission and TC. One (or more) of those is a speed sensor to ensure the input speed (from the flywheel) and the output speed (based on the selected gear) are within an expected range. If you don't re-program the PCM, you'll get all kinds of errors on the dash (depending on what advanced options you have, like cruise control) because it's getting unexpected results. It's still drivable, since YOU are in control of the gears, not the TCM like in the 8-speed, but annoying at best.

Now, none of this should have any effect on 2WD vs 4WD in the transfer case - all you're doing is switching the "gear" inside the TC to drive the front driveshaft in addition to the rear.

 

[818Gladiator]

There are a number of sensors in the manual transmission and TC. One (or more) of those is a speed sensor to ensure the input speed (from the flywheel) and the output speed (based on the selected gear) are within an expected range. If you don't re-program the PCM, you'll get all kinds of errors on the dash (depending on what advanced options you have, like cruise control) because it's getting unexpected results. It's still drivable, since YOU are in control of the gears, not the TCM like in the 8-speed, but annoying at best.

Now, none of this should have any effect on 2WD vs 4WD in the transfer case - all you're doing is switching the "gear" inside the TC to drive the front driveshaft in addition to the rear.

I broke my front driveshaft on my last outing, I believe this is the problem. I have unplugged ALOT of things for random reasons/breaking things, and ran my jeep with literally no issues. You can unplug a crap ton of things and nothing ever shows up on dash. I think this has to do with the fact that I have a BASE model jeep with literally no options, it’s a base sport with roll up windows and manual locks. The only time I got a dash light is when I severed a wire that goes to the diff, I got a 4WD error on dash. But truck ran normally still in 4WD. I repaired wire and fault went away

 

[818Gladiator]

i can see how it could potentially cause some dash lights/things of that nature by not reprogramming. But what I was hearing on the gladiator sounded like a clear mechanical noise coming from the front end

 

[818Gladiator]

I am upgrading to Revolution Gears 1350 driveshafts. I will throw the front in myself and the rears the shop is doing next week.

 

[OHJeeper]

I broke my front driveshaft on my last outing, I believe this is the problem. I have unplugged ALOT of things for random reasons/breaking things, and ran my jeep with literally no issues. You can unplug a crap ton of things and nothing ever shows up on dash. I think this has to do with the fact that I have a BASE model jeep with literally no options, it’s a base sport with roll up windows and manual locks. The only time I got a dash light is when I severed a wire that goes to the diff, I got a 4WD error on dash. But truck ran normally still in 4WD. I repaired wire and fault went away

I saw your later post that it was the driveshaft. I guess my point was even though we both drive manuals, Jeep has put all kinds of sensors on these things to throw errors, but none of them are actually controlling the transmission or transfer case - that's still up to you and me, the drivers

So, the initial diagnoses of "you didn't reprogram the PCM for the new ratio and that broke something" was a load of ?. You may have gotten dash light errors, but that's the extent of the damage that could have happened to your drivetrain.

Glad you got it (hopefully) sorted out and it wasn't your gear swap! I am 250 miles into breaking mine in (also 5.13) and I LOVE the new gears.

 

[818Gladiator]

I have 37s load E for the last 10,000 miles with the manual. And before that as soon as I brought it home I put 35s on. I lifted and did the 37s at 2000miles. I live in the hills, I have never seen 5-6 gear. I now have a 6-speed transmission again and it’s nice

 

[818Gladiator]

On the 35s in the dunes I blew off my front sport fenders on a hard compression lights tore off, no dash lights… ? jeeps… I have aftermarket fenders now

 

[818Gladiator]

Also… if anyone knows, how do the front gears “break in”?

 

[OHJeeper]

I have 37s load E for the last 10,000 miles with the manual. And before that as soon as I brought it home I put 35s on. I lifted and did the 37s at 2000miles. I live in the hills, I have never seen 5-6 gear. I now have a 6-speed transmission again and it’s nice

Ha! We have almost the exact story. I put 35s on mine when I drove from the dealer to my house when I took delivery.

Got home and wife said go bigger so I went to 37s later that week.

MOPAR lift a month later

Living with a 4-speed for the last 2 years and 23k miles.

 

[818Gladiator]

Ha! We have almost the exact story. I put 35s on mine when I drove from the dealer to my house when I took delivery.

Got home and wife said go bigger so I went to 37s later that week.

MOPAR lift a month later

Living with a 4-speed for the last 2 years and 23k miles.

you lasted longer then I did! That’s a long while on a 4 speed lol

 

[Badunit]

Glad you figured it out. Sure is better than ripping into the front axle again.

 

[818Gladiator]

Glad you figured it out. Sure is better than ripping into the front axle again.

yes that’s true. However they need to rip into the rear diff to change out the rear driveshaft but the shop after the initial transfer case/programming comment has been straight forward and did not charge me for diagnostics time to figure out it was the driveshaft. But I also feel like they should have noticed the driveshaft broken when they handled it or maybe it broke when I through it into 4WD and due to the increased torque from the new gearing… IDK I leave that to the universe to do with it as it likes. All that to say, am letting the shop do the rear driveshaft install, and I will personally be installing the front. And they need to open the rear diff up again

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