40-75D vs 40-97A wheels

How to keep the Cessna 170 flying and airworthy.

Moderators: GAHorn, Karl Towle, Bruce Fenstermacher

Post Reply
User avatar
Vertical
Posts: 151
Joined: Mon Oct 08, 2018 12:41 am

40-75D vs 40-97A wheels

Post by Vertical »

Can any one tell me the difference between these two wheels? Both are 6.00 x 6 with a static rating of 2500 lbs. The data tags show a .7 lb difference in weight (97A is lighter). Are there physical differences that would preclude installing either interterchangably?
User avatar
lowNslow
Posts: 1530
Joined: Mon Apr 22, 2002 4:20 pm

Re: 40-75D vs 40-97A wheels

Post by lowNslow »

The 40-97A wheels are the ones STCed for the 170, the 40-75D are for Cessna 180 - 210 aircraft. The Parker catalog mentions that the 40-75D "may not work with wheel pants due to the wider offset of brake disc".

https://www.parker.com/literature/Aircr ... PC0001.pdf
Karl
'53 170B N3158B SN:25400
ASW-20BL
User avatar
n2582d
Posts: 2808
Joined: Mon Apr 29, 2002 4:58 am

Re: 40-75D vs 40-97A wheels

Post by n2582d »

If you compare the wheels in the link Karl provided you'll find that all the parts are identical except that the 40-75D (the C-180 wheel) uses brake disc 164-03601 whereas 40-97A (the C-170 STC'ed wheel) uses brake disc 164-02601. This explains the weight difference as the 164-03601 has a minimum thickness of 0.327" vs. the 164-02601 which has a minimum thickness of 0.205" The C-180 disc uses a dual piston brake assembly p/n 30-52N whereas the C-170 disc is mated to the single piston brake assembly p/n 30-63A. The only other difference I noted was that the 40-75D assembly comes with a "dust shield" -- what I would call a hub cap, p/n 157-00900. So if you found a good deal on 40-75D wheels and wanted to interchange them with your corroded 40-97A wheels you could do it as long as you kept your 30-63A brake assembly and 164-02601 disc (or 164-12601 chrome disc). But the logbook entry should read something to the effect of "replaced inner wheel half assemblies p/n 161-03000 and outer wheel half assemblies p/n 162-02700 removed from aircraft xyz ..." rather than "installed wheel assembly 40-75D ..." as the 40-75D assembly includes the thicker disc which is not approved with the 40-97A assembly STC.
Gary
User avatar
Vertical
Posts: 151
Joined: Mon Oct 08, 2018 12:41 am

Re: 40-75D vs 40-97A wheels

Post by Vertical »

Thanks guys. I appreciate it. Happy Thanksgiving.
Post Reply