No engine braking from trans

[Jim53066]

Hi everyone, Newbi from Wisconsin here with a question.

I have been lurking on the boards for a long time, just recently started getting serious about picking up a 1960 -1972 C10 for a (toy) extra vehicle.

I test drove a 66 today that had a 6 cylinder 3 on the tree. While driving down the highway I noticed that when I let off the gas doing 40-45 mph, the truck would coast, there was no engine braking at all. When I went to speed up, there was a lag and then the truck would sort of catch up and drive normal again.

It has been a long time since owning this vintage truck (the 70's) but it seems to me that when ever you let off the gas with a manual trans it should slow somewhat due to the gearing. Am I missing something? Anyone care to make a guess what it could be?

I doubt I will buy this truck because the owner lied to me about past body work, YEA, go figure, adamantly stated that there was no rust, painted 10 years ago and no body work or or patch panels or rust work at all. But that issue bothers me because I have no idea what it could be.

Thanks in advance, Jim

[GVDobler]

I wouldn't expect much braking in 3rd gear. The momentum of the truck, the tired six and 1to1 gear would not put up much of a fight. Do you notice any braking in 2nd gear?

[Jim53066]

Thanks for the reply,

It actually felt like putting the truck in neutral it was just coasting. What bothered me was that there was a time lag when I stepped back on the gas, a hesitation of sorts for about one second, then it caught up to itself and started to power up. I would think it should have some engine braking, I'm guessing it had 4:11 or 4:56 gears as it was wound tight at about 55mph.

Yes, I could tell that there was some slowing in second gear.

Jim

[PGSigns]

I think with that combo you got all it had.
Jimmy

[slorio]

Jimmy:
Depends on what 3 speed it has. If it happens to have the 3 speed with overdrive, they have an extra "clutch" in them that is only engaged when the tranny shifts into overdrive. Did you see an overdrive lever under the dash? Alternatively climb under the truck and see if it has a solenoid sticking out of the side of the tranny on the drivers' side. When the overdrive trannys are not using the overdrive they freewheel much as you describe.
Regards,
Steve
New Orleans

[Jim53066]

slorio

Thanks for the reply, that is a very good possibility. There was a T lever on the right side of the dash that I thought was a throttle lock. The fact that it was free wheeling like you said (best way to describe it) was just bothering me. I knew what it was doing, I just did not know why, or how it could be doing it.

I did not buy the truck, the owner lied about the condition and I was PO'ed after spending hours on the road to look at it.

Thanks, Jim