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Re: Univair tail spring
Posted: Fri Jun 21, 2019 4:32 pm
by GAHorn
One aspect of this issue might be replacing the entire stack instead of only the main spring. If replacing only one spring,...if that spring is slightly overly thick... then it would have less overall impact on fitment.
I have never heard of any failures of the upper leaves in the spring stack...only the lowest/main spring... so that is the only spring I would normally expect to need regular replacement.
Re: Univair tail spring
Posted: Fri Jun 21, 2019 6:01 pm
by cessna170bdriver
George, I had already purchased a main spring before I discovered the pitting on the upper leaves. The new main spring was with a few thousandths of the old spring, which was to be expected, as it was also a Univair spring I had installed in the 1990s. Two of the new Univair upper leaves were 0.030 thicker than the originals and the third was 0.040 thicker. Since you don’t know of any of the upper springs failing, I feel better about keeping my old ones.
Re: Univair tail spring
Posted: Fri Jun 21, 2019 11:33 pm
by DaveF
Total replacement may be rare, but this isn’t a part for which salvage should be the only source. Sounds like Univair thinks their parts are correct.
Re: Univair tail spring
Posted: Sat Jun 22, 2019 1:28 am
by cessna170bdriver
DaveF wrote:Total replacement may be rare, but this isn’t a part for which salvage should be the only source. Sounds like Univair thinks their parts are correct.
That’s exactly what Univair thinks, and I have no Cessna data other than IPC part numbers, and only one measured set of old springs, so I can’t refute them.
Vintage Aerofab spoke at the maintenance forums at the 170 Convention and claim to have a lot of drawings for the older Cessnas and Beeches, so I’m thinking about giving them a call. I doubt we could put together enough orders to make having them produced cost effective, but they might be able to at least verify the dimensions of the original parts.
Re: Univair tail spring
Posted: Wed Feb 26, 2020 7:46 pm
by n2582d
gahorn wrote:If that's not confusing enough, Later 0-1B and subsequent use bracket 0642150-10 and are mated to leaf spring PNs 0642157, 0642156, 0642154, 0642160.
George, to help reduce the confusion here you might want to edit your entry to read, "... leaf spring PNs 0642157, 0642158, 0642159, 0642160." and then delete this entry. Thanks