haunsauto Posted November 28, 2008 Share Posted November 28, 2008 I recently purchased a 1990 mack ch 613 with a t2090 transmission, which instantly changes ranges when the pre select lever is flipped. this truck was set up for a dump bucket when it was new(but has all been since removed) i was wondering if anything could have been removed (such as a pressure regulator) from the transmission that could be the cause of this problem. other than this the transmission is smooth and functions properly,( i just have to go to neutral before flipping the lever) Quote Link to comment https://www.bigmacktrucks.com/topic/6013-t2090-pre-select-problems/ Share on other sites More sharing options...
David Posted November 29, 2008 Share Posted November 29, 2008 You need to take the valve off the top of the transmission to see why the fork rods aren't telling the valve the stick is in neutral or if the valve is not functioning properly. Quote Link to comment https://www.bigmacktrucks.com/topic/6013-t2090-pre-select-problems/#findComment-25460 Share on other sites More sharing options...
haunsauto Posted November 29, 2008 Author Share Posted November 29, 2008 Thanks, for the reply, I haven't tore into it yet, but I will check that out asap . I was thinking valve replacement would probably be necessary. I was just wondering if there anything else I should be looking for that might not be there anymore. Is there just the one valve on this tranmission? I do appreciate your help (anyone have any idea on the cost of this valve)thanks. Quote Link to comment https://www.bigmacktrucks.com/topic/6013-t2090-pre-select-problems/#findComment-25494 Share on other sites More sharing options...
HK Trucking Posted November 29, 2008 Share Posted November 29, 2008 Better fix it before you use it any more, or else be real care to not move the range selector unless the stick is already in neutral..That thing trying to change range while the trans is still in gear will raise hell with the range shift synchronizer, which is a weak link in those transmissions even when they're operating correctly. Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment https://www.bigmacktrucks.com/topic/6013-t2090-pre-select-problems/#findComment-25496 Share on other sites More sharing options...
HK Trucking Posted November 29, 2008 Share Posted November 29, 2008 Another thought:Just in case the "T2090" in your post was a typo, and you actually have a T2060, T2070, or T2080, those transmissions do not have a lockout on the hi/lo range shift, and WILL try to change range as soon as the button is moved, whether the stick is in gear or not. Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment https://www.bigmacktrucks.com/topic/6013-t2090-pre-select-problems/#findComment-25497 Share on other sites More sharing options...
fjh Posted November 29, 2008 Share Posted November 29, 2008 I recently purchased a 1990 mack ch 613 with a t2090 transmission, which instantly changes ranges when the pre select lever is flipped. this truck was set up for a dump bucket when it was new(but has all been since removed) i was wondering if anything could have been removed (such as a pressure regulator) from the transmission that could be the cause of this problem. other than this the transmission is smooth and functions properly,( i just have to go to neutral before flipping the lever)some early trans had an adjustment for the range pin height!Having said that I have added a blob of weld to the bottom of that pin to make it a tad longer it only takes a little 32 of an inch.Lift the range valve off the top of the trans pull the pin out of the trans and add a bit to the bottom off it!Put it back in and give it a try!It may take a couple of trys to get it right,It is alot easier than messing with the adjuster( IF )it has one, some did some didn't. Quote Link to comment https://www.bigmacktrucks.com/topic/6013-t2090-pre-select-problems/#findComment-25498 Share on other sites More sharing options...
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