Straight 450 reverser problem?

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oljoe
430 crawler
430 crawler
Posts: 95
Joined: Mon Feb 13, 2012 10:53 am
Location: Windsor, Missouri

Straight 450 reverser problem?

Post by oljoe » Mon May 12, 2014 3:29 pm

I have a straight 450 loader with a problem. At first startup I drove it about 200 yards in forward and stopped to select a lower gear. When I shifted the reverser back into forward it wouldn’t move. I tried reverse with no luck. I shut it down, checked the oil level “GOOD” and walked back to the shop. I came back about 20 minutes later with a tractor to pull it back but decided to see if it would move on its own. I started it and shifted to forward, pulled the right steering lever and it turned so I headed back to the shop. When I went from forward to reverse to back into the shop it wouldn’t move again. I tried forward and it still wouldn’t move. I shut down again and walked out to get the tractor. When I got back I started the loader, put it in reverse and it back into the shop.
I put a pressure gauge on the accumulator to check the output pressure. The pressure came up to 150 almost instantly then started bouncing between 150 and pegging the gauge after about 10 seconds. In about 60 seconds the pressure started dropping, still bouncing, and finally dropped to a steady 10 lbs.
I pulled the pressure valve out and checked for binding or any kind of gunk but it looked clean.
I’m not sure where to look next any suggestions?

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Tigerhaze
350 crawler
350 crawler
Posts: 2278
Joined: Thu Jul 06, 2006 12:13 pm
Location: West-Central MO

Post by Tigerhaze » Mon May 12, 2014 4:56 pm

Read these threads about your HLR transmission- you should have three pressure readings for Low, High, and Reverse. Your service manual describes the pressure testing and troubleshooting procedures:

http://www.jdcrawlers.com/messageboard/ ... +pressures

http://www.jdcrawlers.com/messageboard/ ... +pressures


http://www.jdcrawlers.com/messageboard/ ... +pressures

http://www.jdcrawlers.com/messageboard/ ... lr+testing
(1) JD Straight 450 crawler dozer with manual outside blade; (2) JD 2010 diesel crawler loaders; (1) JD 2010 diesel dozer with hydraulic 6-way blade; (2) Model 50 backhoe attachments, misc. other construction equipment

oljoe
430 crawler
430 crawler
Posts: 95
Joined: Mon Feb 13, 2012 10:53 am
Location: Windsor, Missouri

Post by oljoe » Fri May 16, 2014 8:01 am

Thanks for the reply Tigerhaze. Here is a thread that I started when I had a transmission oil leak. The last page is where I am now but it’s still not working properly. I bought a new transmission line and replaced the cracked and brazed one. That didn’t help. I still have the buzzing noise and I’m thinking it may be a pressure valve. The transmission pump could be sucking air also. This buzzing noise was not there before I started taking things apart. Any ideas?

http://www.jdcrawlers.com/messageboard/ ... highlight=

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