Ricardo axle bolts

I was as Daytona yesterday with the Ferrari club testing our MR2 CHUMP CAR. I was approached by the Speedway PR Director about giving a ride around the track to the asst. of a FORD VIP. While one of our drivers was out, I had a conversation with the Ford VIP who happened to be involved in completing the development of the 2005-06 Ford GT. We discussed the SLC and that I have a Ricardo yada yada yada. I questioned the axle bolts, and his response was right to the point. (paraphrased)
If you have allen head bolts, replace them. IF you have 10mm hex heads recessed in the washer they are the gen2 Ford fix. There has been no problems with their gen2 fix. I asked about the accufab kit. He stated they use a thicker washer which reduces the shear on the bolts.

I assumed he felt the thicker washer was superior to the only upgraded hardened Ford bolts. If I remember correctly Cam MacIssac had a 10mm hex head shear off.

Today I visited the Ford GT forum and on like page 26 I found the following. (I had to cut and paste to word)

BTW: We ran consistent 2:20+ lap times in a 1985 Toyota 4cyl MR2 Chump Car. I had a GPS tie wrapped in and every session max speed was 132mph. I think the Garmin GPS must be programmed for a max speed of 132. This speed was impressive but I'm sure we exceeded that.

Wayne, this is great info. I hadn't seen this before, but it is succinct and to the point.

Thanks!

I also found this on the Ford GT forum. It sounds like Ford had a gen1 fix which just included thicker washers. When Cam disassembled his half shafts he shared a pic of his original washer along side the much thicker ARP washer. He also had the "upgraded" 10mm hex head bolts. So did Ford actually have three different washers.
1. socket head cap screws with thin washer
2. 10mm hex head bolt with thin washer
3. 10mm hex head bolt with thicker washer
Maybe someone can find find the washer thickness of the original washer, the gen1 washer and the gen2 washer.
If the washers are not the issue ARP offers just the bolts. AL Wohlstrom discovered this several weeks ago. We both went with these for $4.00 a piece.

Thanks Wayne,

I think Al was going to give a parts breakdown when he got the final invoice for all his pieced together solution. I think it was Al that sort-or pieced it together.... Did he ever post the final information?

The best combination will be a 12.9 hex head bolt with a Grade 8 type hardened washer torqued down to the right spec. With that combination you're basically left with just the sheer strength of the bolt as the limiting factor. The sheer point is very, very high.

If you're using an 8.8 bolt or a 10.9 bolt or a non-Grade 8 washer then you just created the weakest link.

Step 1 - buy accufab kit

or

step 1 - believe you can save $100 by buying similar bolts and re-use washer
step 2 - hope step 1 works

meh, i'll stick w/ step 1, it's only $100 extra.

Alex,

Just out of curiosity, what are the specifications of the accufab kit? In other words, what are the grades and ratings of the fasteners and washers?

Thanks.

Cliffbeer2 said:

Alex,

Just out of curiosity, what are the specifications of the accufab kit? In other words, what are the grades and ratings of the fasteners and washers?

Thanks.

Click to expand...

No idea - they're metric so I'd imagine either 12.9 or 10.9. The washers were like 2x the thickness of the ford gt ones.

Does anyone have part number or website for these bolt kits?
Thanks wayne

roots said:

Does anyone have part number or website for these bolt kits?
Thanks wayne

Click to expand...

THe Accufab kit is at Ford GT Parts | More | Ford GT Parts from Accufab Racing here.

I assumed he felt the thicker washer was superior to the only upgraded hardened Ford bolts. If I remember correctly Cam MacIssac had a 10mm hex head shear off.

Yup, they sheared and its a common problem on the ford gt blogs. its worth the $150 for these bolts washers. Otherwise if they shear, the driveshaft can cause a bit of damage flailing around at highway speeds.

Cam,
How thick was your original washer?
How thick is the accufab washer?

My ricardo appears to have the gen2 Ford final upgrade. Hardened 10mm bolts recessed in a 1/4" washer.

I think you originally had the first version which included the socket head cap screws (allen head) with a pretty thin washer.

When in doubt just buy the best.

WMM said:

Cam,
How thick was your original washer?
How thick is the accufab washer?

My ricardo appears to have the gen2 Ford final upgrade. Hardened 10mm bolts recessed in a 1/4" washer.

I think you originally had the first version which included the socket head cap screws (allen head) with a pretty thin washer.

When in doubt just buy the best.

Click to expand...

i didnt measure but i bet the accufab washers are 20% thicker. beefier., you can see form this photo. The bolts also looked HIGH quality. i wihs i coulda used the pre-drilled axle bolts tho. they turned out to be 1/4" too short for the driveshaft axels.. that also seemed to clear up the clunking in the rear end when catching a 2nd.