a440f "klunk" in 4wd high (3 Viewers)

[pradoblivious]

Hey yall, I've developed a periodic "klunk" somewhere in the drivetrain when I'm in 4wd high. At 25mph the klunk happens about every 4 seconds. You can feel it when it happens, both in the gear shifter and in your feet. I think maybe it's coming from my transfer case but not really sure. The trans is an a440f. Any ideas or tips for diagnosing this?

 

[AirheadNut]

Are the hubs locked when you hear the noise? Does it make noise with the hubs unlocked but the transfer in 4wd? I would recommend a thorough visual inspection of the transfer case front output (check for play in the output bearings) and the front driveshaft (check both u-joints and the slip joint for play).

 

[pradoblivious]

Klunk goes away when I unlock the hubs. I'll hopefully have a few minutes to get under it this afternoon and jimmy the driveshaft around.

 

[AirheadNut]

If the clunk goes away with the transfer in 4wd but the hubs unlocked then it seems to me that you'll be looking at the locking hub assembly. Do you still have electric hubs? Sometimes if the motors actuate but the splines don't engage properly then it can make some noise as you drive, especially when cornering or if there is wheel spin.

Hub engagement can be checked with the transfer in 2wd and the hubs locked, rotate the front driveshaft by hand to see if the hub splines lock in.

 

[pradoblivious]

Yes I do still have the electric hubs. I didn't get a chance to get up under there today, but should have some time tomorrow. Thanks as always for your wisdom, I will report back.

 

[pradoblivious]

visually inspected the tc output and front-drive-shaft.. both u-joints look good to me, laying hands on it and wrenching it back and forth I don't feel any play in anything.. Need to get some jack-stands, and then I'll try out rotating the tires with the transfer in 2wd and the hubs locked.

 

[pradoblivious]

Anybody know the part number for manual lockers on an lj78? Something I can hopefully get pretty quick?

 

[pradoblivious]

92 Prado LJ78 front e hub problems - https://forum.ih8mud.com/threads/92-prado-lj78-front-e-hub-problems.1248122/ looks like a good thread.

 

[pradoblivious]

So with the TC in 2wd and the hubs locked, I can freely spin the front drive-shaft. I do hear a bright "click" once when I begin to spin it, but nothing thereafter. If I shake the driveshaft back and forth I hear light "clunking" inside both hub-locks. I took some video will upload asap.

 

[pradoblivious]

This is in 2wd with the hubs locked.

 

[AirheadNut]

Definitely sounds like either one or both of your hubs aren't locking properly. Could be worn contacts, old sticky grease, failed hub motor. You could attempt a diagnosis and repair, or just go with a manual hub conversion. I believe both Cruiser Outfitters @cruiseroutfit and @Radd Cruisers sell kits to convert to manual hubs.

 

[pradoblivious]

After reading through some threads, I think I'll go the aisin route with rad-cruiser's spacer kit.. Thanks for the help!

 

[pradoblivious]

Parts finally arrived today.

 

[VannCruiser]

Parts finally arrived today.

View attachment 3607871

And ????

 

[kgrove]

Parts finally arrived today.

View attachment 3607871

I'd consider painting the outside of those spacers. The metal on mine rusts and I live in a very low rust area. It looks crappy next to Aisin hub locks.

 

[sark]

I'd consider painting the outside of those spacers. The metal on mine rusts and I live in a very low rust area. It looks crappy next to Aisin hub locks.

I learned this the hard way with my replacement axle hubs from Terrain Tamer