Availability ofRicardo transaxles


Ed Sims

GT Owner
Mark IV Lifetime
Apr 7, 2006
7,850
NorCal
Just medium acceleration up slight hill. Maybe 3000 - 4000 rpm in 2nd gear. Then pop, grind, ouch! I'm not a hard launcher & with over 800rwt I am easy on the throttle. I tend to feel it was not driver error/abuse but maybe I could send it to someone to evaluate other than Stillen. They are the Ricardo 3.9s. There may be other failures but people may not want to post about it. This happened in 2011.

Ed
 

ALLRYZE

GT Owner
Mar 10, 2012
48
ATLANTA
Call Aaron Scott at South Ga Corvette in Thomasville, Ga. He's one of the best engine builders in the country and a GT expert. He repaired my GT when 3rd gear split from a known Electron Beam Weld from Ricardo at 3,000 miles. Ricardo put their head in the sand but it was a broadcasted failure. EBI in Anaheim rewelded the gear properly and she's good as new since. There are also guys in Ahaheim that can reproduce "any gear" and keep your numbers matching TA. It takes some searching but I found them all. PM me if anyone needs the numbers. These guys are all world class.
 

Ed Sims

GT Owner
Mark IV Lifetime
Apr 7, 2006
7,850
NorCal
Ricardo won't help me either. We tried. I'm sure your guys in SoCal can do better.

Ed
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
Ricardo won't help me either. We tried. I'm sure your guys in SoCal can do better.

Ed
Ed if you ring gear is still ok then it may be worth a call to SoCal to see how much it would be to fab up a new pinion gear, or complete sets. I am sure a few more owners would want some 3.9 gears. Love mine.
 

Ed Sims

GT Owner
Mark IV Lifetime
Apr 7, 2006
7,850
NorCal
I'm sure it will be less cost than Ricardo's $10K (5 years ago).

Ed
 

Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,526
Greenwood, IN
That appears to be a fatigue failure based on the "beach marks" versus a single "shot"...many cycles over a long time. Is it a stock pinion and final drive?

Scott, I agree with you. As much as can be seen of the fracture surface, it does appear to be torsional fatigue failure of the input shaft. Also some chipped gear teeth on the “spur gear” type teeth in close proximity to the shaft failure. These may have occurred post shaft failure.

Stillen's 3.9 gears.

For this reason, I would not be pointing the transaxle failure finger at Ricardo. We do have a pretty large population of owners with TT/Wipple setup ups generating more than Ed’s 800 rwhp and have not seen postings from them on OE transaxle problems. Perhaps I am wrong...?

When a piece of transmission machinery is designed, the designer needs to know what level power is to be transmitted. A safety factor is then added which may be 30-40% or whatever the manufacturer is comfortable with (possibly from a warranty perspective). Sometimes the factor is less. The higher this over-design factor, the heavier and more costly the end product will be. And Ford was very weight conscience with our car. With some owners sporting 1000+ hp this amounts to a 100% transaxle design safety factor over the OE 550 hp. Pretty generous from Ford/Ricardo. Point here is I do not believe Ed’s posted shaft failure is an OE Ricardo part. Most differential rear gear changes entail a new ring gear an pinon which this shaft failure appears on the pinion shaft.
 
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Lorenzo

GT Owner
Mark II Lifetime
Dec 28, 2008
626
U.S.A.
It would sure be interesting to now just how many have failed because Ed's is not the only one.
Some are surely the result of high horse power as to be expected when limits get pushed beyond design,
Perhaps only a small few have failed to date however my concern is have all of the failures been of the 3:90 set's ?
I would hate to have to go back to the OEM ratio, With my driving style I am really happy with them.
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
Ricardo made about 20 sets for Stillens and Stillens was the only vendor that sold them. I don't understand why the pinion shaft would be any more likely to fail with a different ratio given the shafts dimensions and materials should be the same as OEM. The stresses on the gears themselves are different but the loading on the shaft is more dependent on the engine's torque, not HP, or the final ratio. e.g the stresses on the pinion shaft will be less on an engine puts out 2000 hp at 20,000 rpm than with a engine that puts out only 500HP at 3000 RPM. That said, Ed's engine put out a lot more torque than stock, I think somewhere between 750 and 800, and he drives his car quite a bit. Many others have even more torque, but I doubt that any of them drive their cars as much as Ed.

IMO, either the Ricardo transaxles are not as stout as we think and the only reasons for the lack of more failures are that the heavily modified cars are not driven much, or Ed just happened to get a bum pinion gear that had a defects in it. I think it was the later. At least I hope that was the case or mine gears will also fail sometime in the future.

I remember looking at my pinion's shaft and there is an undercut right need the failure point. I'm not an ME, isn't it better to have a fillet rather than an undercut where the shaft must change diameters? Couldn't an undercut initiate a stress riser?
 
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Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,526
Greenwood, IN
Good point ICE. Shaft step changes in diameters (as we have on this input shaft) are an area of stress concentration. Here are some suggested better design practices dealing with shaft shoulders. (Wish I could resize some of these illustrative pictures for better pagination, sorry).

design factors1.jpg

On a bit of further reflection, I might broaden my failure scenario opinion. I still believe as Scott indicated the failure appears as fatigue. It may be torsional fatigue as I stated earlier, but typically the fracture surface is not in a singular plane which we see on Ed’s shaft. Torsional failures whether fast fracture or fatigue tend to follow a 45 degree helix. See pictures below. Both the crankshaft and axle failures shown are under Torsional loads and exhibit the raised surface type of fracture surface. There may be a bit of a raised area on Ed’s transaxle input shaft, but not much.

Crankshaft failure.jpgBroken_Axle.jpg

Ed’s shaft failure could also be caused by shaft bending which would be represented by a fracture surface more in a singular plane. See loading mode picture of fracture surfaces produced by various loads. This could be caused by an input shaft misalignment when the unit was reassembled in the vehicle. The misalignment causes plus/minus (or tensile/compression) stresses on the shaft surface as it rotates and once a surface defect nucleates a minute crack, a larger crack will grow (usually perpendicular to the surface as shown in the illustration below) until eventually the remaining uncracked shaft material can no longer convey the engine torque and the shaft fails. This fracture surface may be slightly off the fatigue perpendicular axis again as shown below under bending loads.

Fatigue Failure Modes.jpg
 

Luke Warmwater

Permanent Vacation
Jul 29, 2009
1,414
Boondocks, Colorado
Wasn't there someone awhile back starting threads like this who was also hawking them on Ebay?
 

dbk

The Favor Factory™
Staff member
Le Mans 2010 Supporter
Jul 30, 2005
15,187
Metro Detroit
IMO, either the Ricardo transaxles are not as stout as we think and the only reasons for the lack of more failures are that the heavily modified cars are not driven much, or Ed just happened to get a bum pinion gear that had a defects in it. I think it was the later. At least I hope that was the case or mine gears will also fail sometime in the future.

I think it's probably the latter also. It's pretty rare to hear of a busted transaxle, but I've heard of it happening to cars that have high power & cars that have stock power. A buddy of mine *claims* he was driving along normally in a stock power car and he downshifted to 3rd on the freeway and lost the gear. I don't think Peak's yellow car had issues with the stock transaxle until it had a fairly high number of max power mile runs at ~2,000 rwhp. He had to keep his hand on the shifter to keep it in 5th eventually.

I know a car like mine doesn't make the torque at a super low rpm like Ed's does, but I think it still made around 750 rwtq at 4k, which isn't exactly peanuts, and the car has 26,000 miles. Many of those miles were at race tracks or doing some fairly hard driving. I don't think Torrie ever had a problem either, and his car had 48,000 miles, nearly all of them making north of 1k rwhp, so I'd assume he was making a fairly high tq # as well.
 

tmcphail

GT Owner/Vendor
Mark IV Lifetime
Apr 24, 2006
4,102
St Augustine, Florida
Dave = 100% correct in regards to my car and transaxle.
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
Check for lettering on the shaft, if dot peened...

http://www.met-tech.com/fractured-input-shaft.html
 

Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,526
Greenwood, IN
Interesting report and typical of a failure investigation. Surprised they used a dot-matrix marking system on the surface of an ultra strength steel alloy shaft, M300/9310. These high strength materials are very often very susceptable to surface treatment. Should have been possibly shot peened and a different part identification procedure used to preclude stress concentrations. In steels like these, it does not take much to initiate a fatigue crack.
 

Wwabbit

GT Owner
Mar 21, 2012
1,259
Knoxville, TN
Interesting report and typical of a failure investigation. Surprised they used a dot-matrix marking system on the surface of an ultra strength steel alloy shaft, M300/9310. These high strength materials are very often very susceptable to surface treatment. Should have been possibly shot peened and a different part identification procedure used to preclude stress concentrations. In steels like these, it does not take much to initiate a fatigue crack.

+1
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
Can't wait to hear Frank's o-pinion on this. :lol
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
11,475
Belleville, IL
Specail Ed started in third gear. As usual, he has no recollection so his wife doesn't hear about it. Since his clutch is so super-duper, the shaft broke. Look what he did to his shoulder. This kind of stuff happens to long bones all the time. Ask Dr. Atomic GT. He's the master. BTW, it's about time Indy FINALLY offerd up some pictures. Somebody must have finally taught him how to work a computer.
 

andreikoc

GT Owner
Feb 3, 2013
85
Is the input shaft shown in the thread two piece?
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
Is the input shaft shown in the thread two piece?
Output "shaft" pinion gear
 

Mullet

FORD GT OWNER
Le Mans 2010 Supporter
Oct 21, 2008
2,468
Houston Texas
Just medium acceleration up slight hill. Maybe 3000 - 4000 rpm in 2nd gear. Then pop, grind, ouch! I'm not a hard launcher & with over 800rwt I am easy on the throttle. I tend to feel it was not driver error/abuse but maybe I could send it to someone to evaluate other than Stillen. They are the Ricardo 3.9s. There may be other failures but people may not want to post about it. This happened in 2011.

Ed

I've dead hooked 1150 HP from the hit on drag radials on a prepped track 12-14 times PLUS all the other stuff I've done over the last 4 years and haven't broke anything in the tranny(except the stock sub axles which were replaced 3+ years ago). Tranny is stock except for the axles and clutch.