IFS grinding when 4x4 engaged, and axle seals

[sled_dog]

My buddy has a 97 or 98 Tahoe with push button 4x4. He says recently when he tries to engage 4x4 it makes a grinding noise. I figured a bad actuator but I really am not certain. I haven't ridden in it since this started, or heard it first hand. Any thoughts? Also his axle seals at both ends of his front differential are leaking. How big of a pain are these? Hes wondering if it would be about the same cost with all the work to just swap it to straight axle. I can't convince him to lose the stupid body lift he has though.

 

[divorced]

Does it grind when he is sitting still and engages 4x4? It may be a bad motor on the t-case. It could be the t-case or the front actuator if it grinds when he tries to move after selecting 4x4. He is waiting for the light on his button to light up?

I don't know if any special tools are required for the seal replacement. The differential is super easy to remove though.

I wouldn't bother with a sas unless I was having problems with the IFS stuff breaking or wanted to run a big lift with big tires. Conversion kit + Dana 60 + crossover steering parts + custom front driveshaft + leaf springs + new tires/wheels = dinero grande

 

[sled_dog]

Eh as far as the price of a lift it wouldn't be a ton(not cheap of course). He'd go half ton axles, make brackets(school has the chassis fabrication course for this), and low lift so reusing shaft could be feasible(or stock K series one after front output yoke replacement).

I don't know the conditions, stupid of me not to have asked. I'll take a ride in it when I get back to school and figure it out.

 

[K5MONSTERCHEV]

Seals are cake. Pull out the stub shafts (however those can be a PITA), pry out the seals with a prybar and pop new ones in. The grinding, more details please.

Oh and a SAS is money.

 

[sled_dog]

Alright, rode in it today.

First, its no grinding noise(not any kind I associate with the word). To me it sounds like a u joint thats REALLY worn out and flopping the driveshaft around. But there are no vibes(only drove in the parking lot mind you) and when I climbed under, the shaft seemed to have no play in the joints. It only happens when he locks it into 4wd(though we aren't certain it even engages 4x4 right now). Its a pushbutton tcase, makes the noise in either 4hi or 4lo and when he shifts into 2hi it takes a while for it to go away, he said it took a mile the other day. I just couldn't pinpoint where the sound was coming from, other then its definetally originating from the driverside, so that only leaves the tcase, diff housing, drive shaft, and actuation setup Any thoughts?

Oh and it only happens when actually moving, so I doubt its the tcase motor(though I really don't know how that specifically works)

 

[kennyw]

I hope you were in a gravel parking lot testing out the 4x4

It could be a bad CV shaft or u-joints that are dry but not quite sloppy. I had a conversion ujoint that went dry on one side that started making noise, but it took me 3-4 months to figure out what it was. When it finally started getting sloppy I was able to find it...

 

[sled_dog]

CVs spin all the time so I doubt that. Pavement and gravel

 

[K5MONSTERCHEV]

This one is sort of hard. I wouldnt say a CV is bad. A guy came into school, INSISTED the CV was bad, I told him it wasnt. I changed it and the noise was still there. For some reason i cant rememebr what the problem was, I want to say the rear driveline angles (it was lifted). Almost sounds liek the t case. Why not either put it on jackstands and check for the noise, or disconned the front actuator, to take the front diff out of play, and see if its the t case or diff. NP 243?

 

[sled_dog]

Disconnecting the actuator sounds like a plan.

 

[zcarczar]

the easiet way to test 4 wheel drive that I have found is to simply lock it in on pavement and turn to lock and idle till you can feel the truck bind up, then simply back up and allow the truck to unbind itself and shift out of 4wd.

 

[sled_dog]

I disconnected the CAD and it still made the noise. Yesterday he dropped the driveshaft out and it still makes the noise. So its narrowed down to the transfer case. Told him to check all his connections and if possible, pull the motor and ensure good meshing and connections.

 

[K5MONSTERCHEV]

SOunds like you got it!