1) Idle speed specified as 600-650RPM. Not supposed to shift above this RPM... or clunk.
"Perform the reverse interlock adjustment procedure per attached... recheck... for proper operation"
If you still have issues, then replace hooks as follows....
2) I was in error in previous post... #34 and #37 (right/left) is the hook that wears, NOT #33 sorry for confusion
3) If nut(s) #38 are too tight or washers #36 are missing, things will get funky. I adjust #38 as follows. Tighten until nut(s) are snug up against hook. Then back off 1/2 turn. Hooks #34 should be able to move freely but not have slop. This is before hooking up springs to #45. DO NOT REUSE these nuts!
4) 15-20 min job to replace...
a) With drive up and blocked.... use screwdriver to lever rod #45 out of the recesses on the end of #33 that they sit in.
b) Remove nuts #38
c) remove levers #34/37 with springs
d) I recommend new springs, but may not be necessary...however, you have the old ones in your hand at this point.
e) Attach springs to new #34 and 37
f) Remove washers #36 and clean, lube with thin film of waterproof marine grease and replace
g) lube #34 and #37 lightly
h) replace #34 and #37
i) Install new nuts #38 per above
j) attach springs to rod #45
k) use screwdriver to lever/pry #45 back in place on recesses on ends of #33.
View attachment volvo manual REV interlok.pdf
I have a *.pdf of the Volvo Owners Manual for a number of engine/drives that include the 290. Its too big to attach here. PM me with email address if you want a copy.