HJ61 Automatic vibration (1 Viewer)

Joined
Jun 5, 2005
Messages
74
Location
Townsville, Australia
Rightio. I have an automatic (a440f) sitting behind a 12ht. When I casually accelerate up to 70km/h, it changes into 4th gear. The second it changes, I get this nasty fast vibration coming from the rear of the vehicle. I can make this vibration continue if I hold the revs and speed. Although I've only done this for a couple of seconds.
In this same scenario, If I accelerate really slowly instead of casually up to 70 and it changes into 4th, the vibration is only slight. You can definitely feel it but it isn't as harsh neither last as long.
Same scenario again but accelerating quickly, the vibration is non existent.

All other gears change flawlessly (after I adjusted the kick down cable) the uni joints on the driveshaft feel good. There is some diff oil leaking into the rear hubs. I'm changing the bearings and seals this weekend. There is also a little too much back lash in the diff for my liking but I doubt that would be the cause.

Any ideas? Hopefully none that require a transmission rebuild ;)
 
Joined
Jun 5, 2005
Messages
74
Location
Townsville, Australia
Upon a little more investigation, it must be over drive not 4th gear and it seems this is a common problem usually caused by a Torque converter failing. It's not bothering me too much ATM but I'll do the drive shaft uni joints and flush the tranny a couple of times and cross my fingers. Otherwise, I might be taking a long drive down to see Rodney.
 
Joined
Oct 14, 2009
Messages
521
Location
NSW
My HJ60 shifts into 4th gear at around 50kph, and torque converter locks at around 70kph. So it does sound TQ related.

What happens at speeds above 70kph?
 
Joined
Jun 5, 2005
Messages
74
Location
Townsville, Australia
My HJ60 shifts into 4th gear at around 50kph, and torque converter locks at around 70kph. So it does sound TQ related.

What happens at speeds above 70kph?

This is the reason I couldn't find anything about it when I searched '4th gear vibration.' As you said, It is actually when the Torque Converter locks up around 70kph, the vibration starts. 50kmph drives smoothly.
 
Joined
Aug 13, 2015
Messages
14
Location
Tumut
Hey thanks mine has been doing the same for years, did both uni joints still the same, thinking it was an overdrive problem but now realise it is a torque converter problem I have driven it 100k I with this with a lot of towing, when it vibrates I flick it out of overdrive put it back in when little load is on it.
Tom
 

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