Hi everyone. New member to the forum. I recently bought a 1995 Range Rover Classic. I just had the 4HP22 transmission rebuilt as there were issues with the torque converter locking up, the transmission wouldn't go into park properly and would roll, etc. The rebuild was done by a transmission shop who has experience with the 4HP22. The shop said everything worked fine but I think the rpms are too high. It locks up up at 52mph at 3,000 rpm. Based on the service manual I've seen it should be locking up between 1875-2000 rpm. The shop says they can adjust the kickdown cable to lower the shift points, but the main issue I'm having is that when traveling at highway speeds the rpms are high. At 65 mph it's at 2800 rpm. 75 mph is around 3300 rpm. This seems way too high to me. My friend's RRC (1990- same 4HP22 transmission) does 75 mph at 2400 rpm and he's on stock tire size, whereas I'm slightly larger than stock. I'm on stock gearing.

Any ideas why the rpm's are so high? The transmission shop said maybe my alternator is bad an is sending a bad signal to my tach? I don't think this is the issue as the part number on the alternator is a Denso 276334-1353 that appears to work with a P38 (and presumably these are the same or similar enough?). Even if the tach was having a problem the rover can't really go much faster than 75 and it should be able to. Just based on sound alone you can tell it's revving too high (my friend who also has an RRC says mine sounds like it's revving much higher than his).

I get the impression that the transmission shop doesn't want to admit any fault so I'm trying to diagnose any other issues before going back to the shop. Thanks in advance for any advice!!!

 

Sounds like it is not going into overdrive

 

But the torque converter is locking around 52mph in 4th gear. Is there an overdrive once in 4th? What kind of rpms are all of you seeing?

 

If memory serves the rpms your giving are about what you would see if you were in 3rd gear. So if I had to guess you don't currently have 4th gear (overdrive)

 

Thanks for your reply. It is going into 4th though. I am able to count out each gear / shift point when going from 0 to 52mph. Lockup of the torque converter is occurring at 52mph so I am getting into 4th but the lockup is occurring at high rpms and then the rest of the cruising speed is at high (too high) rpms). So that's why I'm confused at what the issue could be.

 

Figured out the problem (with help from another forum). The previous owner put in an alternator for a P38 Rover which has a different size alternator pulley. I swapped itout with the proper sized alternator and the rpms came down to where they should be. So thetpulley size was the issue. All good now...