LIMITED SLIP DIFFERENTIAL - ANTI-SPIN - Dana 30 VOLVO LSD PLUS Information and Pictures on Volvo DIFFERENTIALS 1030 1031 © by Anthony Hyde First release Nov. 2005, Updated March 2012

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Volvo Dana 30 - MARKING eg. 2 6 80 AH 26421X

This webpage fills a literature & picture void on Volvo / Dana LSD internals. I hope you find the information useful. A.H. LSD FUNCTION : (Source - 1979 Volvo green manual) "Two shafts make up the spider for the differential pinion gears. On the side where it is against the differential carrier, each shaft has a V-shaped bevel. The differential carrier is correspondingly designed. When power from the engine starts to drive the vehicle, the shafts glide up the bevelled recess in the differential carrier. This compresses the friction plates behind the differential side gears so the differential assembly brakes (locks up). The bevel angle on the carrier is chosen in such a way that the differential gears are not entirely locked, but a maximum 75% of engine torque can be transmitted to a drive shaft." Modern name = Dana Power-Lok (Source: Reider Racing) The Dana Power-Lok provides approximately 75% more traction than standard conventional "Open" differential. Its two-piece case construction with four pinion mate spider gears provides for more than double the strength of standard open differentials. Durable all steel clutch plates with unique torque applying cross shafts provides for long life positive action.

SECTION 1 - VOLVO DANA-SPICER LSD VERSIONS
SECTION 2 - 240 DIFF IDENTIFICATION 1030 and 1031
SECTION 3 - DIFFERENCES 1030 and 1031
SECTION 4 - CROSS SHAFTS & LSD ISSUES

1st set of five steel friction discs, side gear retainer and side gear. 2nd set is repeated on either side of cross shaft. Each axle is in metal-to-metal contact in diff oil. Pic shows order - external, internal, 3rd plate cupped (like a C), internal, external. Friction Disc Orientation Source: Volvo Green Manual - Rear Axle	Unexpected find on rebuild. One of the two cross shafts had cracked through. Spider gears run either side of the shaft(s). Cross shafts are the most common failure point in Dana 30 LSDiffs	Dana 30 LSD (hex bolt version 2)
The 'spider' is made up of two cross-shafts that interlock and four side gears. Look closer to spot why this LSD wasn't working so well.	Spreader tool - Diff housing was spread 0.3 mm before LSD centre released (max spread 0.38 mm). Figure the tight fit ensures no endplay is possible to alter the crown & pinion relationship. Side arms have a spigot (pin) that fits into the diff housing and this is where it spreads apart.	LSD Carriers (Housings) - small & large carriers bolt together with left-hand threads

THERE are 3 main LSD VERSIONS for 'rear wheel drive' Volvos: (For simplicity I'll term them LSD 1 - LSD 2 - LSD 3. And ALD from about 1993.
The limited slip differential ( LSD ) or in Volvo terminology Anti-Spin, was an optional extra on nearly all Volvo models (up to 850 era) - with the LSD centre fitted up from new only by the Dealership, by replacing the cars original standard diff centre: This at least applied to later 140s, 240s and 740/760 models. Exceptions where the 123GT being fitted in Canada at the Halifax factory with LSD as standard. Plus reportably, the P1800 and 122S could be ordered from the factory with an LSD (Spicer 27), or this could be fitted later by the Dealer (source G.L.)
Dana's Powr-Lok® differential - The New York Times declared Dana's Powr-Lok® differential to be "among the more significant engineering improvements" in automotive history. The Powr-Lok was launched in 1956, so has a long development history.
Al.P. writes 'The reason for special high pressure oil in the limited slip diff is so that the friction plates don't stick together.
Important Note: Volvo termed its gearboxes, differentials & diff centres with much the same letter / number systems, so be clear to what part your referring to. For example Rear back axle models: M27, M30, M31. Gearboxes M30, M31, M40 etc.
'Diff centre assembly' - Volvo uses the term Anti-Spin for M27 and M30 (no M31). Designed by Dana Spicer, these are termed worldwide as Dana 27 (Spicer 27) & Dana 30, with no such thing as Dana 31.
On Volvo exploded part-diagrams, they also use the term for example. 'Märkt 27' (in english 'MARKED 27') to refer to the model version. So the Volvo 'M' probably just refers to the model, as in M30.

A lot of the information below has been refined after knowledgable contributors have contacted me from around the world with updates. This information aims to be as accurate as possible and when new information is provided and proved, this reference list is updated.

	LSD 1 - Spicer 27 with 10 spline axle - Volvo termed this LSD a 'differential brake' with Spicer mentioned in the manual. LSD1 was an option for the following models till late in 1966: 120, P1800, 1800S, PV Duett (544 210). These models will have rear drum brakes. Additional info: 1961 Amazon - lsd now available as an option. The housing hex head bolts are left-hand thread (UNF) Spicer Manufacturing was renamed Dana Corp (in 1946). Spicer brand name Divisions continue in name. There are differences between LSD 1 & the later LSD 2. The Spicer 27 cross shafts are different size to the Dana 30. Length 27 is 103 mm, 30 is 110 mm. Shaft dia for side pinion 27 is Ø15.9, 30 is 17.6. Spacer sleeve hole 27 & 30 both are Ø11 mm.
	LSD 1.5 - Dana 30 with 10 spline axle - Drum brake version has 10 spline. Found in Amazon (120) late 1966 to 70 (for example the Canadian 123 GT) and in 1800S late 1966 to 69 (rear drumbrakes). In Sweden LSD can also be found on some special cars, for example, nearly all police cars had LSD as standard equipment. The 123GT in Canada was fitted at the factory standard with LSD. Lars Björklund. ID plate and 'S' (S = special edition items): If a 123GT ID plate has the number S5145, this indicates an LSD is installed. Number S5324 indicates a Canadian built GT (from the Halifax factory) and does not appear on anything else except a Canadian GT. The 123GT was not imported to the USA by Volvo dealers. With the imported to Australia 123GT version, the LSD was not 'factory fitted'. No 123GT in Australia has any S numbers on it. - George Minassian, Australia. LSD 1.6
	LSD 2 - Dana 30 with 27 spline axle - Disc brakes version has 27 spline. *'HEX head bolt' bolt head protrudes from carrier / housing. An LSD 2 was an option for the following models: 1800E/ES 1970-73. the 140 from 1967-end 1974, and the 240 series to around 1980. 8x housing hex head bolts are special left-hand thread (3/8"x 24 UNF)(Crown wheel bolt threads are standard RH right hand) Note: Socket cap screws from LSD 3 fit, but ultimately do NOT suit as the screw head sticks out too far and interferes with the inside of the diff housing (read won't rotate. I found this terrible fact out myself and have a handful of very expensive socket cap screws I can't use). 27 Spline 'side gear' mates to the 27 spline rear axle shaft
	* There's huge debate over terms 'bolts & screws' and this varies from country to country, and there are exceptions due to the huge variety. I use the following identifier for engineering bolts/screws: "If tightened on the outside by a socket, or spanner, then a BOLT, if tightened using the inner area (screwdriver/allen key) then SCREW. Self tappers are screws. Set screws are threaded over the entire length.
12 tone wheel segments	LSD 3 - Dana 30 with 27 spline axle - *'Socket head Cap Screw' fits into counterbore in carrier / housing (imperial Allen key) Found in later 200 series, 700, 900 - there's a few out there - Europe, UK. 8x housing socket cap screws are left-hand thread (3/8"x 24 UNF) 12 tooth tone ring machined into carrier. Volvo introduced the electronic speedo after 1986 in 240 & 740. The housing is wider, that's why the socket head screws fit in a counterbore.   965, 940 -94, 765 89-90, 740 89-92 = # 8360 725-9 - For normal driving conditions. Torque 60-100 Nm 764 1982-87, 765 1985-88, 740 1984-88 = # 8360 724-2 - For normal driving conditions. Torque 60-100 Nm 764 82-87, 765 85-88, 740 84-88 = # 8360 722-6 - Greater diff. braking effect which makes it suitable for racing or more severe driving conditions. Torque 130-170 Nm.
48 segment tone wheel	LSD 3.1 - Dana 30 with 27 spline axle - (USA car) Optional extra on a 1992 245 3.3:1 ratio (1992 price US$315). This 48 segment tone ring version was used in ABS brake models and would have been the very last before the 'next generation' auto locking diff was introduced in 1993. Note: You can still have a 48T tone ring in the diff and not have ABS brakes fitted.
Auto Lock Diff on 1041 standard solid axle	NEXT GENERATION - The 'automatic locking differential' - ALD (in Volvo speak 'Differential Brake', but ALD better describes the mechanical function of the diff in English, and the ALD term is used in the USA.) 240 series (rear wheel drive) - The ALD was introduced in 1993 model as a factory installed option. Reportably fitted to the '240 Polar' but for a typical 93 240 it may not be fitted. In 1993 the 740 was replaced by the 940. The 940 (rear wheel drive) had ALD fitted to the 1041 with a standard solid axle. The 960 had ALD on the 1045 Multilink with IRS (independant rear suspension). Later in 1996, the 960 had the 1065 on the Multilink MkII (nil on 1055). With ALD, if one wheel spins it locks both axles up to 40 km/h (25 mph) then cuts out when the latching pawl is released by a centrifugal governor & weights, or cuts out when normal traction occurs. The ALD is fitted with friction discs similar to LSD types 2&3, but controlled differently. In summary, ALD is speed limited, where a traditional Dana 30 is always active and engaged. A front wheel drive version of the ALD with TRACS comes standard from the factory starting with the Turbo 850's and continued with newer models. Reportably the differential is a version of the Eaton G80. See complicated parts exploded in next section of article.

LSD CONTINUED: Primary information - The LSD 2 & 3 are size-wise the same, so either will fit or can be retrofitted to 1030 and 1031 diffs. Good news if replacing an old LSD. If your 240/740 is after 1986 and require the electronic speedo, then you will need the tone wheel LSD 3 version. This does not apply to the bolt-on crown wheel or pinion as they are different sizes (more info in Section 2). From 1970, the Volvo / R-Sport LSD #279951-8 (lsd 2) was available. You can still buy new Volvo LSD's (eg. Volvo dealer. Reider Racing, SAM, with most spare parts readily available from SAM in Sweden. OR via the Volvo dealer network for most 'but not all' internal components - price logic on some dealer parts is questionable, other parts reasonable. IPD used to sell a Spicer Pow-R-Lok type 30, 27 spline #4G1012 (LSD 2)
Note: the rear wheel drive LSD for 2, 7 & 9 series standard diffs after approx 1984 are a little different in external carrier shape, and use for instance a different securing bolts & screws (socket cap head) that hold the small and large carrier together. Note: the bolt head size (same left-hand UNF thread) is incompatable with earlier LSD's as the socket cap head pokes out too far and fouls the diff housing. KEEP old LH housing bolts they will be in demand soon enough. Left-hand threads are used in cases where the screw is subject to anticlockwise forces that might undo a right-hand thread.
Specs sheets show 'Limited Slip Friction Torque' 40-110 Ft.Lbs (54-149 N.m). This refers to a check you can do with a torque wrench with both wheels of the ground.

The quality of this website benefits from your feedback, so if you know of changes or have information, please email Anthony

click images to expand - LSD 2 (pic source; Volvo green manual P 46)

LSD 2 common for 1030 diff

ALD rare with 1031 diff

ALD for 740-940 IRS axles (rare)

SAM in Sweden offer this 'competition' Volvo Dana LSD unit. (LSD 2 version in picture) (Pic source: SAM parts website)  DIFF GASKET - Modern diff shops use a silicone liquid gasket, to replace the (expensive) paper gasket. One liquid gasket highly recommended is ThreeBond #1215 (from Japan). Note: with speedo sensor diffs a gasket thickness is a critical dimension FelPro gasket #RDS55019, common since the Dana 30 is on so many Jeep front ends.

German magazine, Auto, Motor & Sport - said years ago "In fast driving you are continually aware of the limited-slip feature because it locks the action of the differential every time you try to drift through a bend. When this lock-up occurs in mid-bend it can be mildly irritating to the driver. For this reason it is better to enter bends fast in order to bring the differential's locking action into play early on. This technique produces a rather clumssy but ultimately effective style of driving."

LSD MARKINGS - examples (Email me your number so we can follow a trend)
LSD 1.5 4 10 68 25193X (axle/diff is manufactured by Hayes and has a Dana 4,10:1 ratio. Fitted to a 1969 former police 121 Amazon
LSD 2 - 2 6 80 A H 26421X (6 Feb 1980)(26421X is Case Assembly for Model 30/181) Don't know exactly what the A H means? In cars chassis, A was the 1980 model year.
LSD 2 - 11 10 83 26421X
LSD 3 - 2 22 85 72728X (22 Feb 1985) (72728X are typical Dana number system) tomb on outside
LSD 3 - 6 22 85 72722X Pic link tomb on outside
LSD 3 - 1992 245 no markings on housing, diff tube axle label says P1216412, 3.31 ratio, T10D065

LSD WEIGHT: 10 kg with crown wheel attached, bearings on ends removed.

Outlined below are two Volvo 240 diff versions. Both are a 'solid live rear axle' with internal size based on the 27 spline axle Dana 30 -> Volvo added a '10' in front of the Dana 30 number to get 1030, and 1031 for the stiffer dual rib case, to probably indicate Volvo manufacture. The diff is part Volvo (Metric) and part Dana (Imperial). For example, the thread system is mostly UNF (Unified National Fine) from the tailshaft flange bolts (Front 5/16 x 24 TPI UNF & Rear diff flange 3/8 x 24 TPI UNF) all the way to the wheel studs (240 = 1/2"x 20 TPI UNF) (740 = M12x1.5 pitch), with diff cover plate bolts and other areas being UNC (Coarse). Metric threads are found on the diff ends where the dust, disc & handbrake assemblies attach. Essentially much of the transmission system starting rearward with the Laycock overdrive / tailshaft flanges / diff / Unis / use imperial dimensions and threads.

How to tell if the junkyard Volvo has an LSD ? - first indicator to look for is a small metal tag (Use LSD oil) attached to a bolt on the diff cover. To mechanically check, you need to jack the whole rear end of the car up so both rear wheels are just off the ground. Rotate a wheel by hand looking whilst looking at the other wheels rotation. If both wheels rotate in the same direction its an LSD, if they rotate opposite each other its standard.
For a running car, you can just do a short quick wheel spin in the dirt and then check for two equal tyre/tire marks.

Volvo 1030 Diff - single rib Dana 30 27 spline to 1980 / 81

The Volvo 1030 (Dana 30) differential is a pretty tough unit mated with beefy Volvo axle diameters of 1-3/8" stepped to 1-5/16", similar in size to some V8's. The 1030 diff with fitted LSD is the most common model out there, found in the 140 & earlier 240 models with 4 cyl engines. In Europe, some Volvo ambulances from the period can be found with a LSD. In the 1970s-80 era, a 140 or 240 with a 4 speed synchromesh gearboxes and a 'carby' engine required a greater range of diff ratios to suit the terrain, hence a full range of ratio options were available (depending on markets) - 3.31, 3.54, 3.73, 3.91, 4.11, 4.30, 4.88:1. Reportably, the 200-series Volvo Dana 30 type differential was manufactured in England, under DANA license. -> Modern Dana LSD versions are called Power Lok. The 1030 holds 1.3 litres of oil. Webpage © Anthony Hyde 2005

Volvo 1031 Diff - dual rib Dana 30 27 spline typically 1981 onwards

The Volvo 1031 - (Dana 30) heavier duty, introduced to all 4-6 cyl models from 1981 onwards. However, the 264 (PRV V6 cyl models) have been fitted with the 1031 from 1969. Most 4 cly 240's came fitted with the 1031 and from what I have seen in ratios of 3.54, 3.73 to 4.11. Outside of Scandinavia, the 1031 with LSD is a less common find than with 1030 diffs. Jonas Borgegård http://www.bakaxel.se/ writes that a number of 1031 housings don't have dual ribs. The 6 cylinder 260's use a 1031 with low numeric ratios eg 3.31, 3.54. John Sargent writes: "The Limited Slip Differential was fitted as a dealer option to certain 1031 rear axles. The LSD add-in for this axle is a Dana Power Lock with Volvo's name on it and a tone ring for cars with electronic speedometer." Differences : The 1031 housing is a bit stronger again than the 1030 evidenced by the extra rib, and beefed up internally with larger diameter gears on the crown and pinion (more info in Section 3).(Volvord in Canada writes: "30 series uses a 7.2" ring gear while the 31 uses a 7.562". This small increase in diameter of the ring gear and the larger pinion gear (1.376" vs 1.406") adds up to a marked increase in strength"). The 'drive pinion gear shaft' diameter & bearings are larger than the 1030 - see pics in Section 3. Note: If trying to fit a different diff ratio (eg. change of crown wheel) from a 1030 diff into it a 1031 diff (or vice-versa) forget it. If you wish to change diff (final drive) ratios, stick to the same diff version componentry. In summary, don't try and mix'n'match the 1030/1031 parts. The 1031 holds 1.6 litres of oil. Ivar Finnvik from Norway writes: we used a 240 Turbo in European Rallycross Championship in the late eighties and the (1031) was the 'one and only axle' to use.

Crown & Pinion - 1030 vs larger 1031

Pinion Shafts - 1030 vs larger 1031

New C & P from Dana

Diff Housings: Left - 1031 with cutout --------------- Right 1031 without cutout Click to enlarge

Diff Housing: Due to the larger 1031 crown wheel, the housing is cast with a cutout The LSD 3 1031 diff housing is cast with a cutout to suit the larger crown wheeldiameter, one of the reasons why the LSD 3 won't fit into a 1030 housing. Pic opposite shows crossover years between 1031 designs Spot ANY more changes ? - please contact me

Volvo Alloy Diff Housing RARE 'Volvo marked' ALLOY 'diff centre'. Bolted to either side of the 'centre' are steel axle tubes with standard 240 attachment points. Fitted to some 240 model production cars in Sweden 1979 & 1980, often in diesel models. Only the 1030 crown and pinion fits (smaller than 1031). Has LSD centre inside. The alloy version to suit the bigger 1031 crown and pinion is super rare and very expensive, thats if you can find one for sale.

Diff knowledge hints from a hot rodder page - the axle outer tubes are pushed into the cast iron carrier. They have weld, but you don't weld steel & cast iron - so the drilled holes (filled with weld) you see in the cast iron housing are there to enable access of the welding rod to the steel tubes. Welds start at the steel and welded in a circle to build up and create a pin on the tubes.

Dana LSD's most often fail through the cross shaft centre hole
You certainly hear reports with one common result - In my case, the LSD worked well for 7 years behind the turbo engine before I noticed the diff not locking up like it used to. I thought the metal to metal clutch discs were worn but one cross shaft had broken instead. Others have found both cross shafts broken. I know a mechanic whom has a bucket full of broken Dana spider cross shafts. Other LSDs have failed fairly quickly after fitting 2nd hand units behind their turbo engines - a full inspection before fitting would be advisable. Reports of Dana LSDs behind modded V8s are not good.

Shaft - Volvo #3845010 - Most shafts have holes in the centre, some don't - ITS REALLY CONFUSING TO FIND A CONSISTANT TREND especially if your shopping for a replacement, you would try and obtain ones without a hole as they would be stronger through the centre section. BUT have a look at the shaft picture below - they are solid shafts, but instead of breaking through the centre, they broke on the ends !

Why do they have holes in the first place ? - depends on the production era - Lars Björklund writes: Up to year 1969, the hole is used to locate a spacer sleeve to hold the driveshafts apart because the driveshaft bearings support each other via driveshafts and the spacer sleeve. Shims are used to adjust the driveshaft end play. Later models have another construction where the drive shaft bearings and the driveshaft are located into the diff ends and held in place with a clamping ring with 4 bolts, and hence up do not need support in the differential cross-shafts as on earlier models.

Link Engineering discussion on Shafts

Jim Williams (Australia) found two broken cross shafts that in-turn resulted in lunched LSD internals. Unit was fitted to a 1969 164 manual overdrive, 3.73 ratio. These old cross shafts had no holes in them. As far as the owner knew they were original. A 1985 LSD in a 1031 diff housing had no holes in the cross shafts either. IF you have information you would like to share, please email Anthony

X-Ray of 2nd cross shaft - 120kV, 150uA

X-Ray of replacement solid cross shaft

1030 Rear Wheel / Axle Bearings: 73 mm OD, Timken U360L. Diff outer oil seal Volvo #383222 (65 ID, 52 OD, 8.5 to 9 section)

CROWN WHEELS - 1030
3.73 : 1 - Volvo #384213 P05 43-11 (the 384213 seems a typical volvo number & is not found in Dana 'Bill of materials')
3.91 : 1 - Volvo #384217 P06 43-11
VOLVO 1220733 P01 43-11 1790 031078 and on the body: 6-22-85 72722X

Differential Gear Ratio determines the number of times the drive/tail shaft (or pinion) will rotate for each turn of the wheels (or ring gear).
If you have a 3.73:1 gear ratio, the drive shaft turns 3.73 times, and the wheel :1 (once).

10 bolt rear cover

Further web reading: http://www.k-jet.org/files/greenbooks/TP30039-2_rear_axle_repairs.pdf Ring & Pinion - the diff experts, some info link DTS - Drivetrain Specialists USA Dana RING GEAR AND PINION TOOTH PATTERN INTERPRETATION Dana 30 Service manual Rear Axle Page 19, Diff Carrier Page 27- (best to source a Volvo Green manual) The Dana 30 LSD CARRIER is most commonly found of the front of Jeep vehicles. Wrangler, Cherokee, CJ5, CJ7. It can be of standard rotation or reverse rotation. (MY4BY.com)

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