I'm installing a curt 11276 hitch receiver on Prius gen3. the instructions advise to remove the right-side muffler support arm and the left side tow-hook bracket. these are held in place by 1.25" x 12mm bolts. the Curt Instructions state that you should torque the new receiver bolts to 86 lb-ft, which seems very high to me. I'm thinking this might strip out or break the welded nuts. Does anyone have the original Toyota spec for the torque for these bolts, when they are used for the tow hook? 11276_INS.pdf (curtmfg.com) https://assets.curtmfg.com/masterlibrary/11276/installsheet/11276_INS.pdf thx in advance!
When I've done these I used the non-judgemental torque setting known as "alot" but if you want to get more specific than that, there's some charts online that will tell you the best torque setting for your bolt size.
Curt Tow Hitch Install Finished!!! if only 30 minutes | PriusChat ^ This thread, installing same brand of hitch, says 65 lb/ft, near the bottom of first post. There's very likely a spec for the original bolts, in Repair Manual; I looked for a few minutes, couldn't figure out where it would be. Too: the hitch company may want a bit higher torque? 65~85 isn't too crazy; lug nuts are 76.
I didn't have to remove the exhaust on my persona at all I may have moved one of the rubber hangers or something for a second and pull down on it to put the side with the hoop or whatever over there on the exhaust side and then swing the other side up and put all the bolts in loose initially shake it make it happy and then blast them all in with my DeWalt battery operated gun when everything touches let it wrap on it 3 seconds or something I did not torque these bolts and they stayed in towing lawn mowers and trailers and all kinds of stuff through two or three states and I just took off the hitch the other day because all the generation threes are turning into piles of poop so we're not driving them let alone towing anything with them at the present time
thx Mendel. I installed two hitches of far, on a gen3. once about 4 years ago and I torqued it to 50 lb-ft. and today again and torqued to 45 lb-ft. the curt guide says 86 lb-ft. another vendor's hitch install guide says ~65 lb-ft. I didn't like the way the wrench was continuously tightening but never really reaching the rated torque. I didn't want to snap the weld nut off from inside the frame and create a bunch of extra work for myself. there are these conical tooth washers that come in the curt kit and these potentially just keep flattening out as you crank down on them, giving the wrench that weird feel, like the bolt is going to strip out. I used blue Loctite today on the bolts, just to make myself feel better. Not sure it will help. I should note a few things: my last installation at 50 lb-ft seemed to do well for a few years and perhaps 20-30 moderate tows. And I cannot remember on the first install, but on this one, the old bolts which held in the tow hooks, were not even torqued to 10-15 lb-ft. I set the wrench and tested it as I backed the out. now these bolts were probably in the tow hooks for 8-9 years so they may have gotten loose with time, but they were basically not tight at all. It's probably not a bad idea to test and tighten the old bolts every 2-3 years.
