Steering Column/Gear question

[thedudeabides86]

Hey everybody,

How's it going? I have a question about my steering column. When I put my 72 C20 in reverse, the shifter drops a tad and doesn't make contact with the backup lights. What might cause this issue? If I hold the shifter in place where the R is on the plastic guide, the backup lights will be on, but if I let go, it drops a little. It's still in reverse and will back up, it's just the slight drop of the shifter I wonder about. Is there something in the column that might be worn making this happen? I've attached a picture of where the indicator sits when I'm not holding up the shift lever. Hopefully, this makes sense? I should mention, when I put the truck in drive, I can lift up on the shifter and it will drop down into the gear per se, not allowing you to bump it out of gear unless you pull back on the lever. Thanks.

[dmjlambert]

I have limited experience, but others will probably chime in and correct me. There is a detent mechanism on the steering column in the engine compartment, if it has sharp edges and doesn't slope off where it exits the reverse position that would help. My steering column rebuilder guy said mine was worn and he did some work on that section so it's in better condition. I don't have a before picture of it that I can find but here's a current picture.

.
I understand there is also a detent mechanism in the transmission to make the different positions of the lever on the transmission click into place. These things need to be adjusted to work in harmony. You can turn off the engine, chock your wheels, set brakes, temporally disconnect your linkage and click the transmission lever through the gears and see if it seems to still have some gusto in the detents.

[HO455]

To amplify what dmjlambert said. I've pointed to wear areas on the detent. The red arrows point to the contact areas that the selector (Yellow arrow) rubs on. On high mileage, low maintenance vehicles the selector may have worn the high areas off the detents. A bit of grease from time to time will cut down on this wear.

There are two adjustments associated with your problem. First is to do as dmjlambert posted and verify the transmission detents are working. Then reconnect the linkage and check to see if the shift indicator points correctly. If the pointer is too far one way or the other you can adjust it at the linkage where it connects to the column.

In the second photo the green arrow points to the lock nut on the linkage adjuster. Once loose you can slide the linkage up and down as shown by the red arrow. The idea being you loosen the nut and place the shift indicator where you want it and retightened the nut.

The second adjustment has to do with the neutral safety switch on the top of the steering column. (Photo #3 green arrow) There is are 2 hex headed screws that hold the switch on the column. The screws go through slotted holes that allow the switch to be adjusted (Red arrow)so the starter will only operate if the truck is in park or neutral. In addition the reverse light switch in in the same block. Occasionally the tab on the switch is so worn or damaged that the switch won't operate correctly. For example the reverse lights may only work when coming from park but not from drive.

I hope this helps if not just ask and we will figure it out.

[LockDoc]

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Another thing I would do is to spray some PB Blaster into the opening where the shift lever goes into the column, in the cab. Be sure and hold a rag under it if you have nice carpet. Spray above and below the lever then pull it up towards you, then push it back down towards the dash a few times.. I have found that the shift lever hangs up in that area and a good shot of penetrating oil/lube helps a lot. The lever has to move up and down to shift through the gears and make it lock into the detents.

LockDoc

[basketcase]

I had a 77 once with that problem. My problem was gravity. The floor and cab mounts were rusting badly and the weaker they got, the lower the cab sat. Every so often it wouldn't align and even fail to stay in reverse so I would have to adjust the shift rod shorter to center the pointer in neutral again. Then it would be fine until gravity wanted to be a ***** again.

Tom

[thedudeabides86]

Originally Posted by dmjlambert

I have limited experience, but others will probably chime in and correct me. There is a detent mechanism on the steering column in the engine compartment, if it has sharp edges and doesn't slope off where it exits the reverse position that would help. My steering column rebuilder guy said mine was worn and he did some work on that section so it's in better condition. I don't have a before picture of it that I can find but here's a current picture.
Attachment 2381100
.
I understand there is also a detent mechanism in the transmission to make the different positions of the lever on the transmission click into place. These things need to be adjusted to work in harmony. You can turn off the engine, chock your wheels, set brakes, temporally disconnect your linkage and click the transmission lever through the gears and see if it seems to still have some gusto in the detents.

Thanks for the input. Pardon me for sounding dumb, but where is the trans linkage I should disconnect? Under the truck at the trans? I'll do some research and Google-Foo and see what I can come up with. I'll take a look at it this weekend and keep everyone posted with how it goes.

[thedudeabides86]

Originally Posted by HO455

To amplify what dmjlambert said. I've pointed to wear areas on the detent. The red arrows point to the contact areas that the selector (Yellow arrow) rubs on. On high mileage, low maintenance vehicles the selector may have worn the high areas off the detents. A bit of grease from time to time will cut down on this wear.

There are two adjustments associated with your problem. First is to do as dmjlambert posted and verify the transmission detents are working. Then reconnect the linkage and check to see if the shift indicator points correctly. If the pointer is too far one way or the other you can adjust it at the linkage where it connects to the column.

In the second photo the green arrow points to the lock nut on the linkage adjuster. Once loose you can slide the linkage up and down as shown by the red arrow. The idea being you loosen the nut and place the shift indicator where you want it and retightened the nut.

The second adjustment has to do with the neutral safety switch on the top of the steering column. (Photo #3 green arrow) There is are 2 hex headed screws that hold the switch on the column. The screws go through slotted holes that allow the switch to be adjusted (Red arrow)so the starter will only operate if the truck is in park or neutral. In addition the reverse light switch in in the same block. Occasionally the tab on the switch is so worn or damaged that the switch won't operate correctly. For example the reverse lights may only work when coming from park but not from drive.

I hope this helps if not just ask and we will figure it out.

Ah, gotcha on the neutral safety switch. I'll check that out as well. Thanks!

[thedudeabides86]

Originally Posted by LockDoc

-
Another thing I would do is to spray some PB Blaster into the opening where the shift lever goes into the column, in the cab. Be sure and hold a rag under it if you have nice carpet. Spray above and below the lever then pull it up towards you, then push it back down towards the dash a few times.. I have found that the shift lever hangs up in that area and a good shot of penetrating oil/lube helps a lot. The lever has to move up and down to shift through the gears and make it lock into the detents.

LockDoc

Thanks LockDoc. I'll try that out as well.

[thedudeabides86]

Originally Posted by basketcase

I had a 77 once with that problem. My problem was gravity. The floor and cab mounts were rusting badly and the weaker they got, the lower the cab sat. Every so often it wouldn't align and even fail to stay in reverse so I would have to adjust the shift rod shorter to center the pointer in neutral again. Then it would be fine until gravity wanted to be a ***** again.

Tom

Tom,

That sounds like a lot of work. The cab and floor pans are pretty solid, but I'll crawl under there and do some checking to see what I find.

[basketcase]

Probably not the problem then.
Tom