bad knock that goes away when engine rpms increase?

grumpyvette

Administrator
Staff member
" hey grumpy? Ive got a bad sound similar to a rod knock that goes away when engine rpms increase?
As a test I disconnected the flex plate from the torque converter and the noise dropped to almost nothing, my friends say its a cracked flex plate, any ideas?"




THERE'S A GOOD CHANCE YOUR FRIENDS ARE CORRECT ITS A FAIRLY COMMON PROBLEM ON HIGH PERFORMANCE CARS WITH A STOCK FLEX PLATE!
ID also look at the motor mount bolts and bell housing bolts as those can also cause noise at low rpms that goes away as rpms increase
and the symptoms you describe tend to indicate a cracked flex plate
IF YOUR GOING TO PUT THE TIME AND EFFORT INTO REPLACING A DECENT ENGINES FLEX-PLATE, BUY AN SFI CERTIFIED FLEX-PLATE< STOCK ONES ARE SO THIN THEY CRACK CONSTANTLY IF SUBJECTED TO HIGHER STRESS, SFI cert ones are about 35% thicker and welded much better

3571.jpg

brokenflexplate.jpg


sum-g100sfi_cp.jpg

tcclearance.gif


don,t forget to use ARP flexplate bolts with LOCTITE thread locker on the bolt threads, the ARP bolts are much stronger and less likely to come loose or shear off!

flexplatebolts.jpg

loctite.jpg
 
Back
Top