Toyota had HUGE problems with rear-ends in 1977-1986 Cab/Chassis trucks sold to RV motorhome industry converters due to overloading of the rear drive axle. It is and was so bad that there was a recall on Toyota motorhomes.
This problem is most prevalent with the dual rear wheel equipped Toyota motorhomes that were NOT original equipped with a factory "floating axle" dual rear wheel rear-end (1977-1987). Many of the converters of the time used adapter kits to install dual rear wheels on their conversions to increase the weight
capacity of the chassis to match the weight
the RV manufactures's where installing on the chassis which lead to the problems of broken axles and accidents. There are also instances of the problem of rear axles breaking also occuring in Toyota motorhomes equipped with a single rear wheels do to overloading of the coach by the owner with all their "junk" they believe that is needed for camping.
The problem was resolved to a certain degree during the 1986-1987 production years when Toyota began to offer a true dual rear wheel "floating axle" rear-end in their cab/chassis trucks sold to RV converters. Apparently problems still continued through the early 1990's as in 1993 Toyota stopped selling their cab/Chassis trucks altogether to the RV industry do to liability issues.
This issue "may" not apply to this particular Toyota motorhome as it appears to be a single rear wheel model HOWEVER you should be aware of the Toyota rear axle issues in Toyota motorhomes from this 1977-1987 vintage/era and check out any Toyota chassis RV coach rear-end carefully prior to purchase as single rear wheel Toyota motorhomes from 1977-1987 are NOT totally immune to this serious safety issue/problem.
Attached is a PDF file containing information concerning this critical issue that everyone considering a Toyota motorhome should read: